Tucson monthly climate reports for 2023

The new year began on a wet note when a winter storm impacted the area as the calendar turned from 2022 to 2023. Although not as wet as what occurred when the calendar changed from 2021 to 2022, it did mark the first time in over 70 years that precipitation was recorded on back-to-back New Year's Day (1949-1951). Above normal temperatures then prevailed across the area until mid-month when an upper air pattern change occurred which would bring a series of winter storms to the area along with cooler than normal temperatures for the remainder of the month.

The first winter storm impacting the area during the second half of the month brought valley rain and mountain snow over a three day period from the 15th to the 17th. The passing of this system would usher in a much colder air mass that would remain across the area through the remainder of the month. Daily low temperatures across the metro from the 19th to the 22nd would range from the mid 20's to the lower 30's. A second winter storm, this one colder than the mid-month storm, would bring light snow/flurries down to the valley floor on the 23rd and early on the 24th. Afternoon temperatures on the 24th struggled to get out of the 40's. This system reinforced the cold air in place with lows on the 24th to 26th in the mid 20's to the lower 30's. The last five days of the month saw highs in the 60's and lows in the 30's.

The monthly average temperature of 51.6° is TWO degrees below normal and ranks as the 60th warmest January on record. Temperature extremes for the month ranged from a high of 80° on the 13th to a low of 27° on the 26th. The high on the 13th of 80° set a new daily record eclipsing the old record of 78° which originally occurred in 1928 and was later tied in 2000, 2006 & 2018. Below is a listing of some interesting temperature items that occurred during January.

• 14 straight days with below normal lows (18th to 31st); most in January since 16 straight days in 2011 to start the year.
• 14 straight days with lows colder than 40° (18th to 31st); most since 18 straight days which occurred from December 30, 2010 to January 16, 2011
• 11 straight days with lows 35° or colder (19th to 29th); most since 11 straight days which occurred from December 22, 2007 to January 1, 2008
• 4 straight days with lows 32° or colder (24th to 27th); most since 5 straight days which occurred in January 2017 (25th to 29th)
• # of January days with lows 28° or colder (3); most in January since 5 days in 2013
• # of January days with lows 32° or colder (6); most in January since 12 days in 2013
• # of January days with lows 33° or colder (9); most in January since 13 days in 2013
• # of January days with lows 35° or colder (11); most in January since 15 days in 2013

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 3" with localized higher amounts across the Catalina Foothills. The International airport, which is the official recording spot in Tucson, recorded 1.76" which is just under one inch above normal and ranks as the 16th wettest January on record, tied with 1907. Some interesting rainfall items which occurred during January. These items are for the airport only.

• 3 straight days with daily rainfall totals of 0.40" or greater (15th to 17th); this is a record for January and the most in the calendar since 3 days in July 2021 (23rd to 25th)
• 2 straight days with daily rainfall totals of 0.50" or greater (16th & 17th); this is tied for a January record and the most in the calendar since 3 days in July 2021 (23rd to 25th).
• New daily rainfall record set on the 16th with 0.59". This broke the old record of 0.37" from 1987 and its the first daily rainfall record at the airport since July 25, 2021

One month remains in climatological Winter and so far it has been cooler (52.8° or -0.6°) and wetter (3.03" or +1.23") than normal. The 3.03" at the airport would rank as the 35th wettest Winter on record if no precipitation is recorded in February..

The Climate Prediction Center forecasts for temperature a 35% chance that they will end up below normal & a 32% chance that they will end up above normal. The forecast for precipitation is a 43% chance that they will end up below normal & a 24% chance that they will end up above normal.

The February outlook for Tucson, issued on January 31st by the Climate Prediction Center, slightly favored above-normal monthly mean temperatures (35% above vs 32% below) and favored below-normal total precipitation amounts (43% below vs 24% above).

The month was dominated by an active weather pattern that resulted in a roller-coaster ride in temperatures and an unusual number of windy days for February. This was thanks to a handful of winter storms that moved across the area that brought precipitation in the form of valley rain and mountain snow and on occasion, snow down to the valley floor (14th, 15th & 26th). The most significant winter storms occurred on the 14th-15th, 17th, 21st-22nd & 26th.

The monthly average temperature of 53.3° is 2.9° below normal and ranks as the 54th coolest February on record. This is the fourth February in the last five years that the average monthly temperature was below normal. Temperature extremes for the month ranged from a high of 80° on the 5th to a low of 28° on the 16th.

La Niña conditions that were present during the previous two winter seasons (December through February) continued into a third straight winter. This would be the third occurrence since 1950 that La Niña conditions would be present in the equatorial Pacific for three consecutive winters (1973-74 to 1975-76 & 1998-99 to 2000-01). Based on past La Niña impacts during the winter season, the temperature and precipitation outlook for Tucson, issued November 17th by the Climate Prediction Center, called for the following:

• a 23% chance that the seasonal mean temperatures will be below normal
• a 44% chance that the seasonal mean temperatures will be above normal
• a 43% chance that the seasonal total precipitation will be below normal
• a 24% chance that the seasonal total precipitation will be above normal

The seasonal average temperature of 53.0° is 1.3° below normal and goes into the record books as the 54th warmest on record, tied with Winter 1910-11 & Winter 1968-69. Temperature extremes ranged from a high of 80° on January 13th & February 5th to a low of 27° on January 26th. Ten days recorded freezing low temperatures at the airport, which is normal. However, this is two more days than what occurred during the previous two winter seasons combined. Additionally, there were two record temperatures that were established. They were:

• A record warm low temperature on December 4 (59°; old record 56° in 1946)
• A record high temperature on January 13 (80°; old record 78° in 1928, 2000, 2006 & 2018)

Precipitation across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages, and CoCoRaHS, ranged widely from 2.50" to 6.50" with the highest totals occurring in Oro Valley and along the Catalina foothills. The Tucson International airport, which is the official recording location in Tucson, recorded 3.62" which is just under one inch above normal and ranks as the 26th wettest Winter season on record.

Dating back to 1950, there have been twenty-five occurrences that La Niña conditions were present during climatological winter. Winter 2022-23 became only the 2nd La Niña winter to record above-normal seasonal precipitation. The other occurrence was Winter 1984-85 when 6.09" was recorded. Note: Winter seasonal total precipitation for the twenty-five La Niñas were compared to the 30-year climatological normal total for Tucson at the time of occurrence.

The yearly mean temperature of 52.4° is around 2.5° below normal and ranks as the 59th coolest January/February period on record.

Precipitation across the metro area has ranged widely from 1.50" to 4.50" during the first two months of the year. The Tucson International airport, the official recording location in Tucson, has recorded 2.35" which is three-quarters of an inch above normal and ranks as the 32nd wettest January/February period on record.

The March outlook from the Climate Prediction Center for Tucson slightly favors below-normal monthly mean temperatures (34% below vs 33% above) and above-normal total precipitation amounts (37% above vs 30% below).

The Spring season outlook from the Climate Prediction Center for Tucson favors above-normal seasonal mean temperatures (46% above vs 21% below) and below-normal total precipitation amounts (41% below vs 26% above).