Tucson monthly climate reports for 2024

The January outlook from the Climate Prediction Center, issued on December 31st, for Tucson favored below-normal monthly mean temperatures (59% below vs. 8% above) and above-normal total precipitation amounts (46% above vs. 21% below).

The new year started on an unsettled note with a pair of weather systems moving across the area. The first system brought scattered very light showers to the area mainly on the 3rd while the second, much stronger, system brought widespread light rain, gusty winds, and some light snow to isolated areas of the metro on the 7th. Wind gusts of 30 to 40 mph were recorded before a cold front passage with temperatures dropping up to 10 degrees in 10 minutes with frontal passage.

The colder air mass led to the first widespread freezing event for the 2023-24 Winter season for the metro area with lows on the 9th in the 20s, coldest near washes as those areas dropped down into the low 20s. Chilly morning lows continued through the 13th. High temperatures from the 4th through the 12th were in the 50s. The exception was upper 40s on the 8th and lower 60s on the 10th.

An odd occurrence happened on the 12th (High 58°, Low 29°) and 13th (High 66°, Low 33°) when the high temperature was exactly double the low temperature both days. This daily double has only happened 23 times since 1894 with the most recent occurring in January 2016 (29th & 30th).

A gradual warming trend then took place over the next week with highs warming into the 70s from the 17th through 20th while lows moderated into the 40s on those days.

A significant pattern change brought widespread rain and mountain snow to the area over three days from the 21st through the 23rd. Three-day rainfall totals across the metro area ranged from 0.60" to 2" with localized spots up to 2.75". The airport set two daily rainfall records for this event. On the 21st, 0.81" was recorded which shattered the previous daily record of 0.40" from 1933 and 1982. Two days later, on the 23rd, 0.60" was recorded, which broke the previous daily record of 0.56" from 1985. This is the first January to set two daily rainfall records since 1993 when three were set.

Daily high temperatures from the 21st through the 26th were mostly in the 60s before high pressure aloft settled in during the last five days of the month, which resulted in daily highs mostly in the mid to upper 70s. The exception was on the 29th when the first 80° high temperature of 2024 was recorded. The climatological first date is February 1st.

The monthly average temperature of 52.8° is 0.8° below normal and ranks as the 40th warmest January on record, tied with 1943 & 1983. Temperature extremes for the month ranged from a high of 80° on the 29th to a low of 28° on the 9th.

The December 31st precipitation outlook for Tucson from the Climate Prediction Center favored above normal precipitation (40-50%) for January. Rainfall amounts, using several sources like rainlog.org, the Pima County Regional Flood Control District gages, and CoCoRaHS, ranged from 1.00" to 2.50" with localized spots up to 3.50". The Tucson International Airport, the official recording spot in Tucson, recorded 1.77" which is just under an inch above normal and ranks as the 16th wettest January on record. The first four months of the hydrological water year, October through January, has been wetter than normal with 3.71" being recorded at the airport, and ranks as the 44th wettest first four months of the water year.

One month remains in climatological Winter and so far it has been warmer (54.8° or +1.4°) and wetter (3.24" or +1.60") than normal. The historical Winter ranking with one month left stands at 32nd wettest.

Looking ahead into February

A strong El Niño will continue in the equatorial Pacific through the end of Winter. The February outlook from the Climate Prediction Center for Tucson favors near normal monthly mean temperatures (36% near vs 33% for both above & below) and above-normal total precipitation amounts (52% above vs. 15% below).

The February outlook for Tucson, issued on January 31st by the Climate Prediction Center, favored above-normal total precipitation amounts (52% above vs 15% below) and favored near-normal monthly mean temperatures (36% near Vs 33% for both above and below). The month was split into two periods, a wet first 11 days then a mostly dry and warm remainder of the month.

The first 11 days of the month were active as several winter storms moved across the area with rainfall occurring across the metro areas every day except for on the 4th and 5th. A thunderstorm on the 2nd produced brief heavy rain and pea-sized hail. On the 6th, strong gusty winds occurred in advance of another winter storm. The airport recorded a peak gust of 59 mph which is the highest February gust in the past 50 years. The coldest storm of the month impacted the area on the 10th with widespread valley rain and a little snow, mainly across the southeast portion of the metro area including Vail. The high temperature on the 10th of 48° was the 4th coldest February high this century.

The monthly average temperature of 57.1° is 0.9° above normal and ranks as the 26th warmest February on record. Temperature extremes for the month ranged from a high of 86° on the 25th to a low of 35° on the 12th. This is the 26th February on record in which the official site didn't record a low temperature of 32° or colder. The last February that this occurred was in 2021. The high & low temperatures of 76° & 61° on the 26th have occurred together only once before since 1894, on May 3, 1915.

A strong El Niño was forecast to peak during the 2023-24 Winter season. El Niño typically brings an increased chance of wetter than normal conditions during the Winter months, December, January, and February. However, there was no model consensus to swing the chances of a wetter-than-normal winter for Tucson. Based on that assessment the temperature and precipitation outlook for Tucson, issued on November 17th by the Climate Prediction Center, called for the following:

• a 33% chance that the seasonal mean temperatures will be below normal
• a 33% chance that the seasonal mean temperatures will be above normal
• a 33% chance that the seasonal total precipitation will be below normal
• a 33% chance that the seasonal total precipitation will be above normal

There were several active periods this past winter that helped shape the season. Those active periods were 1) several days before Christmas; 2) mid-January; and 3) the first 10 days of February. The numerous winter storms that moved across the area brought much-needed precipitation in the form of valley rain and mountain snow. This helped improve drought conditions across the metro area from severe classification at the start of winter to moderate classification at the end of winter.

The seasonal average temperature of 55.5° is 1.2° above normal and goes into the record books as the 11th warmest on record, tied with Winter 1995-96 & Winter 2008-09. Temperature extremes ranged from a high of 86° on February 25th to a low of 28° on January 9th. Four days recorded freezing low temperatures at the airport, which all occurred in January. This is the third Winter on record in which all of the 32° or colder low-temperature days occurred in January. The other Winters were 1940-41 and 1962-63. This is also the 8th Winter season on record that recorded less than 5 days with lows of 32° or colder.

Precipitation across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages, and CoCoRaHS, ranged widely from 3.25" to 6.00" with isolated spots up to 8". The Tucson International Airport, which is the official recording location in Tucson, recorded 4.63" which is nearly two inches above normal and ranks as the 15th wettest Winter season on record. The airport set three daily rainfall records (1.25" on December 22nd; 0.81" on January 21st and 0.60" on January 23rd). The last Winter season to record three or more daily rainfall records was Winter 1997-98 (3).

The yearly mean temperature of 54.9° which is normal and ranks as the 27th warmest January/February period on record.

Precipitation across the metro area during the first two months of the year has ranged widely from 2.25" to 4.50" with isolated spots up to 5.50". The Tucson International Airport, the official recording location in Tucson, has recorded 3.16" which is almost an inch and a half above normal and ranks as the 14th wettest January/February period on record. The water year rainfall (October 1 to February 29) total of 5.10" ranks as the 35th wettest first five months of the water year on record. 

The March outlook from the Climate Prediction Center for Tucson favors below-normal monthly mean temperatures (45% below vs 22% above) and equal chances for either below, near, or above-normal total precipitation amounts.

The Spring season outlook from the Climate Prediction Center for Tucson slightly favors below-normal total seasonal precipitation amounts (34% below vs 33% above) and equal chances for either below, near, or above-normal seasonal mean temperatures.

The March outlook for Tucson, issued on February 29th by the Climate Prediction Center, favored below-normal monthly mean temperatures (45% below vs 22% above) and equal chances for either below, near, or above-normal total precipitation amounts. The monthly average temperature was below normal which marks the third straight March that was below normal. On the precipitation side, it was wetter than normal.

The first five days of the month had highs in the 70s and lows being either 46° or 47°. Cooler temperatures settled in from the 6th to the 8th as a weather system passed through the state. This system brought widespread valley showers, high-elevation mountain snow, isolated thunderstorms, and small hail on the 7th and scattered lighter showers on the 8th. High temperatures on these three days were in the 60s.

Dry conditions and warmer temperatures, with highs in the 70s, returned to the area from the 9th through the 14th

Another weather system moved through the state on the 14th and 15th. This system brought scattered showers, high-elevation mountain snow, and a few thunderstorms to the area on the 15th. High temperatures from the 15th through the 17th were in the 60s before warming back into the 70s from the 18th through the 23rd. The exception was on the 22nd when highs across the metro area were in the lower 80s.

The third storm system of the month to impact the area brought gusty winds, widespread valley rain, and high-elevation mountain snow on the 24th and 25th. High temperatures once again were only in the 60s. Dry conditions and warmer temperatures returned to the area from the 27th to the 30th with highs in the lower 80s on the 29th and 30th.

The last storm system of the month brought gusty winds, widespread valley rain, and mountain snow on the 31st, Easter Sunday. This is the first widespread precipitation event to occur on Easter since 1999 when it snowed across parts of the metro area 25 years ago.

The monthly average temperature of 59.7° is just over two degrees below normal (-2.2°) and ranks as the 54th warmest March on record, tied with 1947. This is the third consecutive March that was below-normal and the first occurrence of three or more consecutive below-normal Marches since a five-March period from 1979 to 1983. Temperature extremes for the month ranged from a high of 82° on the 29th and 30th to a low of 41° on the 18th. The monthly high of 82° was cooler than the February monthly high of 86°. Since 1895, this is the 16th time on record, first since 2014, that the March monthly high was cooler than the February monthly high. The monthly low of 41° is the second warmest March monthly low on record, bested by the 46° monthly low from March 2014. This is only the seventh March on record in which the monthly low temperature was not in the 20s or 30s.

Rainfall amounts across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages, and CoCoRaHS, ranged widely from 0.75" to 1.75 " with localized spots up to 2.50" near the mountains. The International airport, which is the official recording spot in Tucson, recorded 1.25" which ranks as the 24th wettest March on record.

The average yearly temperature of 56.5° is just under one degree BELOW normal (-0.9°) and ranks as the 30th warmest on record, tied with 1911, 1934, 1980, 2005, and 2020, through the end of March.

Rainfall at the Tucson International Airport, the official location in Tucson, of 4.41" is 2.17" ABOVE normal & ranks as the 12th wettest January through March period on record. It is the wettest first quarter of the calendar year since 2010 (4.51"). The water year rainfall is at the halfway mark with 6.35" being recorded which ranks as the 31st wettest first half of the water year period on record.

Each month so far in 2024 has recorded above-normal rainfall at the airport (January: +0.93"; February: +0.55"; March: +0.69"). This is the first time that a year, when compared to their respective normal periods, has started with three above-normal months since 1992 and it's only the 6th such occurrence since 1952.

When you add December 2023, which was 0.51" above normal, the four-straight months of above normal precipitation is the first occurrence since Summer 2006 when June through September each recorded above normal rainfall.

The April outlook from the Climate Prediction Center for Tucson favors above-normal total precipitation amounts (45% above vs 22% below) and equal chances for either below, near, or above-normal monthly mean temperatures.

The April outlook for Tucson, issued on March 31st by the Climate Prediction Center, favored above-normal total precipitation amounts (45% above vs 22% below) and equal chances for either below, near, or above-normal monthly mean temperatures. Thanks to the 3rd wettest April day, April 2024 goes into the record books as the 12th wettest April. On the temperature side, April 2024 was cooler than normal. The last cooler-than-normal April was in 2010.

The first day of the month started on a wet note, no foolin', as a weather system brought widespread showers and a few thunderstorms to the metro area. A few of the thunderstorms produced heavy rain for April, in a short period. For example, a thunderstorm moved across the airport between 5:57 pm and 6:12 pm with just over half an inch (0.53") being recorded. Normal rainfall for the April is 0.24". The daily total on the 1st at the airport was 0.88" which ranks as the 3rd wettest April day on record but did not set a daily record. No foolin'! The wettest April 1st is 1.17" from 1999.

Outside of the wet 1st day of the month, the remainder of the month was dry with the typical roller-coaster ride in high temperatures that occurs in April as weather systems pass by to our north bringing periods of enhanced breeziness. The strongest winds of the month occurred on the 5th when a cold front moved through the area with the airport recording a wind gust of 52 mph. This is the highest April wind gust since April 28, 2017, when a 51-mph gust was recorded. The warmest time of the month was from the 18th to the 23rd when daily highs were in the lower to mid-90s. The airport hit 95° for the first time in 2024 on the 22nd. The 1991-2020 normal first 90° date is April 24th.

The monthly average temperature of 67.3° is just under one degree below normal and ranks as the 42nd warmest April on record. Temperature extremes for the month ranged from a high of 95° on the 22nd to a low of 39° on the 7th. Interesting climate tidbit: The monthly low temperature for April was in the 30s while the March monthly low temperature was in the 40s. This has happened only one other time, in 2017 (March 40°; April 37°). Only one temperature record was set. It was for a cool high on April 1st with a high temperature of 55°. This broke the old cool high for April 1st of 56° which occurred in 1949. The 55° high on the 1st is the coolest April high temperature since 2011 (57° on the 9th) and the 12th coolest April high temperature on record (since 1895). The record April cool high is 50° from April 12, 1912, and April 5, 1921.

Most of the rain that fell across the metro area for the month occurred on April 1st with lingering light showers on the 2nd. Totals recorded across the metro area using sources like rainlog.org, the Pima County Regional Flood Control District gages, and CoCoRaHS, ranged from a tenth of an inch (0.10") to nearly one inch (1.00"). The International Airport, which is the official recording spot in Tucson, was one of the wetter spots across the metro area with a monthly total of 0.88". This ranks as the 12th wettest April on record and wettest since 2004 (1.05").

The average yearly temperature of 59.1° is just under one degree below normal and ranks as the 33rd warmest on record through the end of April, tied with 1997, 2004, and 2013. This is the second consecutive year in which the average temperature for the first third of the calendar year is below normal.

Rainfall at the Tucson International Airport, the official location in Tucson, of 5.29" is 2.81" above normal & ranks as the 8th wettest January through April period on record. The water year rainfall total of 7.23" ranks as the 26th wettest on record.

The May outlook from the Climate Prediction Center for Tucson calls for equal chances (EC) of below, near, or above for both total precipitation amounts & monthly mean temperatures.

Rainfall amounts across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages and CoCoRaHS, mostly was zero with localized spots up to a tenth of an inch. The International Airport, which is the official recording spot in Tucson, recorded zero rainfall. This is 26th May since 1895 that no rain was recorded at the official site in Tucson.

Spring 2024 was cooler and wetter than the 1991-2020 normal. If you recall the Spring season outlook for Tucson, issued on February 15th by the Climate Prediction Center, slightly favored below-normal total seasonal precipitation amounts (34% below vs 33% above) and equal chances for either below, near, or above-normal seasonal mean temperatures.

The seasonal average temperature of 68.1° was below the 1991-2020 normal of 68.9° and goes into the record books as the 33rd warmest on record. The seasonal average temperature was below normal for back-to-back Springs for the first time since the Springs 1979 & 1980. Temperature extremes ranged from a high of 103° on May 28th to a low of 39° on April 7th.

Rainfall amounts across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages, and CoCoRaHS, ranged from 1.50" to 3.50". The International airport, which is the official recording spot in Tucson, recorded 2.13" which is 1.13" above normal. This ranks as the 18th wettest Spring on record. The majority of seasonal rain fell during the first third of the Spring season with little to no rain after April 1st through the end of May. In fact, the Spring season ended on the 60 day consecutive day streak with no rain being recorded at the airport. This ranks as the 5th longest Spring dry streak on record, tied with 2020.

2024

The average yearly temperature, through the end of May, of 62.9° is 0.6° below normal and ranks as the 29th warmest on record. The average yearly temperature is below normal at the end of May for the 7th time since 1982.

Rainfall at the Tucson International Airport, the official location in Tucson, of 5.29" is 2.68" above normal and ranks as the 11th wettest January through May period on record. The water year is above normal since October 1st at 7.23" which ranks as the 27th wettest water year to date with four months left in the water year calendar.

The first twenty days was dry and hot with high temperatures between 100° and 110° (20th) and lows in the mid to upper 60s (1st thru 5th) and in the 70s (6th thru 20th). The first signs of monsoonal moisture moving into the area occurred on the 20th when strong easterly winds pushed dew point values into the 50s and lower 60s. The average daily dew point of the 20th was 51° versus the 40° on the 19th.

Abnormally high surface dew point values remained in the area for the last 10 days of the month with daily averages being in the 60s. Below is a list of some astonishing numbers with dew point data in Tucson dating back to 1946.

• 10 straight days with the average daily dew point in the 60s. Previous June high is 4 straight days in 2000 (27th to 30th)
• Daily average records were set/tied on six straight days (22nd: 66°; old record 63°); (23rd: 67°, old record 64°); (24th: 65°, old record 59°); (25th: 64°, old record 63°); (26th: 63°, old record 61°); (27th: 60°, record tied).
• The daily average on the 23rd, 67°, tied the highest June daily average previously occurring on June 29th & 30th in 2000.
• Hourly observations were in the 70s for 19 hours while from 1946 to 2023 there were a total of 20 hours.
• There was 16 straight hourly observations with dew points in the 70s (5 pm June 22 to 8 am June 23).
• New monthly hourly dew point value was set with 74° at 6 am on the 23rd.
• The 74° dew point on the 23rd is the 4th highest hourly dew point recorded on record behind 77° on August 3, 1989; 76° on August 10, 1966 & 75° on August 22, 1959 & August 11, 1975.

There were two notable monsoon storms during the last ten days of the month.

• A 73 mph wind gust from a thunderstorm hit the Tucson Int'l airport on the 21st. Dating back to 1946, this is the highest wind gust recorded in June. The previous high was 68 mph from a thunderstorm on June 30, 2013.
• Up to two inches of rain fell across portions of the city on the afternoon of the 22nd producing flash flooding which resulted in over a dozen swift water rescues.

The monthly average temperature of 89.3° is 3.2° above normal and ranks as the 4th hottest June on record. Temperature extremes for the month ranged from a high of 110° on the 20th to a low of 66° on the 2nd & 3rd. The month recorded 29 triple-digit high temperatures is one short of the June record of 30 days set in 2013. The 33 consecutive days of triple-digit highs, which began on May 27th and ended on June 28th, goes into the record books tied as the 6th longest on record.

Rainfall across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages and CoCoRaHS, ranged widely, as is usually the case during the convective season, from a tenth of an inch to nearly three inches. The International airport, which is the official recording spot in Tucson, recorded just over one inch (1.07") which is slightly over eight-tenths of an inch above normal and ranks as the 10th wettest June on record..

The average yearly temperature, through the end of June, of 67.2° is right at normal & ranks as the 20th warmest on record, tied with 1943, 1954 & 2002. The streak of triple-digit high temperatures for year of 33 consecutive days (May 27 to June 28) is tied with 2002 (June 12 to July 14) for the 6th longest on record dating back to 1895.

The July outlook from the Climate Prediction Center for Tucson favors above-normal monthly mean temperatures (55% above vs 12% below) and ever so slightly favors above-normal total precipitation amounts (34% above vs 33% below).