Climatology 101: Wet Fall, cool November

Nov2015

Cool and dry are the operative words to describe November in Tucson.

November 2015 officially goes down as the 45th warmest & 38th driest in Tucson since 1894. The 45th warmest stat is a bit misleading, as the average high, average low and average temperature all came in below normal. You have to go back to 2004 for the last time November accomplished that trifecta.

While November was dry, Fall 2015 was the third in a row with above normal rainfall. Tucson International Airport registered 4.81″, which is well above the average of 2.75″ between September 1st and November 30th. Last time this stretch happened? Fall 1994-1996.

Below is the complete November/Fall 2015 climate report, compiled by our friends at NWS Tucson.

November 2015 saw a roller coaster ride in high temperatures with four separate periods with highs in the upper 70s to lower 80s. In between these periods, Pacific weather systems moved across the area with isolated to scattered showers, a few thunderstorms, gusty winds and daily highs in the 60s. The first freezing temperature of the 2015-16 Winter season occurred at the airport on November 29th. The historical average first freezing date is November 25th.
The average temperature for November of 59.1°, although ending up being below normal by 0.7°, ranks as the 45th warmest on record. For the first time since 2004 and the 16th November since 1950, all three temperature averages ended up being below normal. (see table below) Temperature extremes for the month ranged from a high of 84° on the 2nd to a low of 30° on the 30th.
November 2015 daily high temperature departure from normal November 2015 daily low temperature departure from normal
The images above (click on them for larger view) show daily departure from (1981-2010) normals. Below normal is blue and above normal is red.
Rainfall amounts across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages and CoCoRaHS, mostly ranging from 0.10″ to 0.60″ with localized spots near 0.80″. At the airport, which is the official recording location in Tucson, 0.16″ was recorded which ranks as the 38th driest November on record.
November 2015 stats
Month
Normal
Departure
Average high temperature
73.4°
73.5°
– 0.1°
Average low temperature
44.9°
46.1°
– 1.2°
Average temperature
59.1°
59.8°
– 0.7°
Rainfall
0.16″
0.57″
– 0.41″

Fall 2015 climate report for Tucson Fall 2015 climate recap for Tucson Arizona
Headlines
18th warmest on record
14th wettest on record
11th straight Fall with above normal temperatures
3rd straight Fall with above normal rainfall Click to enlarge
Another warm Fall with an average temperature of 71.9° which ranks as the 18th warmest Fall on record. This is the 11th straight Fall that the average temperature has been above normal. Temperature extremes ranged from a high of 102° on September 12th to a low of 30° on November 30th.
Fall 2015 daily high temperature departure from normal Fall 2015 daily low temperature departure from normal
The images above (click on them for larger view) show daily departure from (1981-2010) normals. Below normal is blue and above normal is red.
Fall was another wet one for Tucson with rainfall amounts across the metro area, using several sources like rainlog.org, the Pima County Regional Flood Control District gages and CoCoRaHS, mostly ranging from 4″ to 7″ with localized spots near 9″. At the airport, which is the official recording location in Tucson, 4.81″ was recorded which ranks as the 14th wettest Fall on record.

Since climatic normals were established in the early 1950’s, there have been five occurrences in which the airport has recorded above normal rainfall for 3 or more consecutive Fall seasons. (see table below)

Most consecutive Fall seasons with above normal rainfall since 1950
# Years Period average Normal Normal period
4 1969 to 1972 4.85″ 2.26″ 1931-1960
4 1982 to 1985 5.52″ 2.83″ 1951-1980
3 1962 to 1964 4.53″ 2.26″ 1931-1950
3 1994 to 1996 4.39″ 3.40″ 1961-1990
3 2013 to 2015 3.92″ 2.75″ 1981-2010
Fall 2015 stats
Season
Normal
Departure
Average high temperature
84.2°
84.2°
0.0°
Average low temperature
59.5°
57.3°
+ 2.2°
Average temperature
71.9°
70.8°
+ 1.1°
Rainfall
4.81″
2.75″
+ 2.06″
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