arizona climate summary1 arizona climate summary may 2020 summary of conditions for april 2020 april...

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Arizona Climate Summary May 2020

Summary of conditions for April 2020

April 2020 Temperature and Precipitation Summary

April 1st – 14th: The first week of April saw temperatures near average across the state with clear skies and dry

conditions as the storm track remained well north of Arizona. Daytime highs in the southwest deserts were in the mid to

upper 80s while the higher elevations and northern Arizona saw highs in the upper 40s to the mid 50s. Lows at night

remained below freezing at the higher elevations and were in the upper 50s to lower 60s in the southwest deserts. By the

8th a low-pressure system off the California coast moved into Arizona bringing light rain and slightly cooler temperatures

to the state. On the 8th, Yuma has 0.12” of rain and on the 9th the Grand Canyon Airport had 0.25”. The heaviest rainfall

on the 9th was across northern Arizona, while some parts of central Arizona had less than 0.10”. A second, stronger and

colder low-pressure system moved in on the 11th. This system lingered through the 14th with widespread rain and some

snow at the higher elevations. Snowfall included 1.5” at Bellemont, and rainfall totals included 0.55” at Flagstaff, 0.36”

at Grand Canyon AP, 1.08” at Kingman, 0.06” at Nogales, 0.08” at Phoenix Airport, 0.65” at Prescott, 0.13” at

Scottsdale, 0.14” at St. Johns, 0.18” at Sonora Desert Museum, 0.07” at Tucson, 0.64” at Valle, 0.20” at Window Rock,

0.75” at Winslow, 0.18” at Yuma, 0.08” at Carefree, 0.45” at Cottonwood, 0.02” at Douglas, 0.46” at Payson, 0.13” at

Phantom Ranch, 0.07” at Picacho Peak, 0.15” at Pinnacle Peak, 0.23” at Seligman, 0.27” at Show Low and 0.68” at

Williams. During this storm event daytime high temperatures in the southwest deserts dropped into the upper 70s while

the higher elevations saw temperatures in the upper 40s in the daytime and 18 to 30 degrees at night.

April 15th-30th: By the 15th the storm system had cleared out of the state and temperatures rebounded 5 to 10oF back up

to near average values. The state remained dry through the 17th when another very weak system crossed northern

Arizona dropping measurable precipitation in the Flagstaff area and trace amounts of rain in Prescott, Kingman,

Cottonwood, the Grand Canyon, and St. Johns. The heaviest rain was 0.20” at Bellemont on the 18th and 0.02” at

Flagstaff on the 19th. The state was completely dry the rest of the month as high pressure moved in and remained over

the southwest bringing clear skies and much warmer temperatures. By the 22nd daytime temperatures in the southwest

deserts reached the mid 90s and by the 24th temperatures reached the low 100s. The coldest spots saw daytime

temperatures in the low 70s. Nighttime temperatures at the highest elevations remained at or below freezing, but in the

southwest deserts nighttime temperatures were in the upper 60s and lower 70s. Many northern Arizona cities broke high

temperature records as this heat wave arrived earlier than usual.

In This Issue: Overview of April, graphs of the April daily maximum and minimum temperatures, precipitation, mean

daily dew points for Flagstaff, Phoenix, and Tucson; April climate statistics, maps of mean monthly maximum and

minimum temperatures, precipitation, dew points, wind speeds for April; short-term drought maps for the beginning and

end of April 2020; Long-term Drought Map through April and graphs of the mean April and annual temperature and

precipitation for the period of record for Tucson, Phoenix, and Flagstaff, graphs of the cumulative precipitation for the

calendar year for Flagstaff, Phoenix, and Tucson. Data are preliminary and are from the National Weather Service

Forecast Offices in Flagstaff, Phoenix and Tucson.

**Note: The discrepancy between the Statewide Temperature and Precipitation values for Phoenix, Flagstaff and

Tucson and the daily values in their graphs are due to the reporting times. Statewide Temperature and Precipitation

values are taken at 5pm, while official daily records at the airports are taken from Midnight to Midnight.

Dr. Nancy J. Selover, State Climatologist

http://azclimate.asu.edu 480-965-0580

Edited by Nancy J. Selover

© 2020 Arizona State Climate Office

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April 2020 Daily Temperature, Precipitation, & Dew Point for Flagstaff, Phoenix, and Tucson

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FLAGSTAFF CLIMATE STATISTICS

April 2020

This April had no significant ranking for

temperature, or precipitation.

Avg Max Temp(F) 60.3 Normal 58.2

Avg Min Temp(F) 29.3 Normal 28.5

Avg Mean Temp(F) 44.8 Normal 43.3

Departure from Normal (F) +1.5

Highest Monthly Avg Temp (F) 50.4 in 1989

Lowest Monthly Avg Temp (F) .36.2 in 1975

Highest Temp this month (F): 79 on 28th, 29th

Lowest Temp this month (F): 16 on 15th

Record High (F): 80 on 4/29/1992, 4/7/1989

Record Low (F): -2 on 4/02/1975

Temperature or precipitation records this month:

29th HiMax 79 set, previous record 78 set in 1992

Flagstaff Number of Days of:

Minimum Temp 40oF or higher 2

Minimum Temp 30oF or lower 19

Maximum Temp 70oF or higher 7

Maximum Temp 50oF or lower 5

Heating Degree Days 599 Normal 649

Cooling Degree Days 0 Normal 0

Degree base 65oF

Total April Precipitation 0.83”

Normal April Precipitation 1.15”

Departure from normal -0.32”

Greatest 24-Hr Precipitation 0.37” on 12th

Total Precipitation Year-to-Date 6.38”

Departure from Normal -1.10”

Total April Snowfall 0.2” Normal 7.1”

Record April Snowfall 58.3” in 1965

Number of Days:

Clear 24

Partly Cloudy 5

Cloudy 1

Greatest April Precipitation 5.62” in 1965

Least April Precipitation: Trace in 1991 and 2008.

Average Wind Speed 7.8 mph

Highest Peak Gust 45 mph from 220o on 2nd

PHOENIX CLIMATE STATISTICS

April 2020

This April was the 19th warmest, and was tied for

the 10th driest with 1967 and 2012.



Avg Mean Temp (F) 74.2 Normal 72.7



Lowest Monthly Avg Temp (F) 62.4 in 1967

Highest Temp this month (F) 104 on 29th


Record High (F): 105 on 4/22/2012, 4/29/1992,

4/20/1989

Record Low (F): 35 on 4/10/1922


26th HiMax 102 set, previous record 101 in 1992

30th HiMin 75 set, previous record 74 in 2007

Phoenix Number of Days of:







Degree base 65oF



Departure from normal +0.20”

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Greatest 24-Hr Precipitation 0.08” on 11th


Least April Precipitation 0.00” in 2018, and 32

other years.

Precipitation since January 1st 3.55”

Departure from Normal +0.45”

Number of Days:

Clear 16

Partly Cloudy 14

Cloudy 0


Highest Peak Gust 36 mph from 220o on 8th

TUCSON CLIMATE STATISTICS

April 2020

This April was the 13th warmest and was tied for the

9th driest with 2019 and 1936.



Avg Mean Temp(F) 69.6 Normal 67.0



Lowest Monthly Avg Temp (F) 57.8 in 1975

Highest Temp this month (F): 102 on 29th


Record High (F): 104 on 4/21/1989, 4/20/1989

Record Low (F): 27 on 4/04/1925


26th HiMax 99 tied, first set in 1996

26th HiMax 102 tied, first set in 1992

30th HiMin 68 set, previous record 66 in 1955

Tucson Number of Days of:







Degree base 65o



Departure from normal -0.24”

Greatest 24-Hr Precipitation 0.07”on 11th

Total Precipitation Year-to-Date 2.09”

Departure from Normal -0.75”


Least April Precipitation 0.00” in 2018 and 27

other years.

Number of Days:

Clear 24

Partly Cloudy 1

Cloudy 0


Highest Peak Gust 42 mph from 200o on 8th

Data are from the National Weather Service and the

National Climatic Data Center and are preliminary.

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Wind Speeds for April:

Day Phoenix Flagstaff Tucson

(mph) Avg Max Avg Max Avg Max

1 6 21 13.1 36 6.8 26

2 8 25 18.3 45 9.2 30

3 6.1 23 6.9 31 8.8 28

4 6.6 20 10.9 36 8.1 27

5 7.8 23 12 37 9 31

6 9.3 24 13.6 40 8.5 31

7 8.1 23 5.7 28 6.5 26

8 9.8 36 9.7 36 11.9 42

9 4.6 22 7.4 30 5.5 21

10 5.2 21 3.8 27 6.6 26

11 6.7 21 5.7 25 4 32

12 7.8 23 12.5 34 6.5 23

13 6.9 25 5.2 30 8.4 31

14 8.6 24 6.3 24 7.4 27

15 5 21 6.4 28 5 20

16 6.9 23 10.7 40 7.7 38

17 9.4 29 7.2 32 9.2 34

18 7.4 23 8.2 27 8.4 33

19 5.8 16 5.8 29 6.2 21

20 8 28 7.7 29 6.9 22

21 6.8 33 5.7 26 7.8 36

22 5.7 23 4.8 27 7.7 26

23 8 29 6.5 32 7.4 30

24 6.5 20 4.5 24 6.3 24

25 5.2 17 5.6 24 5.7 21

26 6.8 24 7.8 36 6.9 19

27 7.4 26 7.3 34 6.9 24

28 5.2 18 3.6 21 6 20

29 5.6 20 5.2 29 5.1 20

30 5.8 19 6.7 34 7.3 24

Dew Points for April:

Daily Average Dew Point (oF):

Day Flg Phx Tuc

1 36 24 25

2 37 26 24

3 35 22 23

4 32 24 25

5 30 23 22

6 34 29 21

7 38 31 24

8 37 33 26

9 36 27 25

10 37 33 24

11 41 34 34

12 43 36 34

13 36 30 23

14 30 23 15

15 23 16 17

16 26 17 18

17 29 15 27

18 31 26 26

19 36 27 30

20 37 22 27

21 38 29 26

22 36 28 27

23 36 30 23

24 32 27 23

25 35 25 24

26 36 27 28

27 33 25 24

28 34 25 28

29 36 30 31

30 38 29 32

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The

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April 2020

The minimum temperatures ranged from 8oF at Snowslide Canyon to 52oF at Phoenix. The lowest maximum temperature of 54oF was recorded at Bright

Angel Ranger Station and the highest was 108oF at Havasu and Tacna. The highest rainfall totals were 2.70” at Snowslide Canyon and 2.10” at Mormon

Mountain. The lowest average dew point was 21oF at Window Rock and the highest was 47oF at Mohave and Yuma. The highest reported peak wind gust

was 38 mph at Salome and Fort Mohave. Average wind speeds ranged from 3 mph in the Phoenix area and Payson to 12 mph at Pioneer and Show Low.

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April 2020

The lowest average minimum temperature was 17oF at Sunset Crater and the highest was 51oF at Phoenix Airport and Union Pass. The highest average

maximum temperature was 89oF at Phoenix, Coolidge and Tacna and the lowest average maximum temperature was 49oF at Bright Angel Ranger Station.

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Short-term Drought

A strong winter storm the last week of March and a weak low-pressure system in early April dropped enough rain and snow on northern Arizona to improve

conditions in northern Coconino, Navajo and Apache counties. The Chuska Mountains improved from Moderate Drought (D1) to Abnormally Dry (D0), and

Severe Drought (D2) was removed from northern Apache County and replaced with Moderate Drought (D1). The area of the state with no drought increased

from 76.6% to 80.6%, and the area in Severe Drought (D2) decreased from 10.9% to 6.8% Further improvement is unlikely until the monsoon begins in late

June or early July. Worsening conditions are possible as hot, dry conditions are anticipated until the monsoon begins.

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Long-term Drought

The long-term drought map for April shows hydrologic drought, based on precipitation and evaporation using

the Standardized Precipitation Evaporative Index (SPEI) and the Standardized Precipitation Index (SPI) over

the past 24-, 36-, and 48-months. This depiction is for water resources, not short-term drought (rangeland

conditions). The long-term drought conditions across the state show very slight improvement in April in

northeastern Arizona as the storms this month dropped most of their scant precipitation on northern Arizona.

The northeast continues to be the driest area of the state. Further improvement is unlikely until the monsoon

begins in July.

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April 2020

Minimum temperatures were cooler than average in much of southern Arizona, particularly southeastern Arizona. Northeastern Arizona was 2-5oF warmer

than average. Maximum temperatures were 1-4oF warmer than average in the eastern half of the state and 0-4oF cooler than average in the southwest. The

April precipitation ranged from 2% of average to 400% of average across the state. The wettest conditions were reported in central and southern Coconino,

Navajo and Apache counties, while most of southern Arizona was drier than average. Most of Mohave County received much above average rainfall, though

southern Mohave County was extremely dry.

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Calendar Year 2020

Minimum temperatures have been cooler than average in Mohave and Yavapai counties and southern Arizona while northeastern Arizona and La Paz County

have been 1-3oF warmer than average. Maximum temperatures have been 0-2oF warmer than average across northern Arizona and 0-2oF cooler than average

in southern Arizona. Prior to April, the winter storms had a southerly track, but April’s storms moved across northern Arizona, reducing the differences

between cooler temperatures to the south and warmer conditions to the north. Since January 1st, precipitation has been wetter than average in eastern and

western Arizona and drier than average in north and south-central Arizona.

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2020 Water Year

Minimum temperatures have been within 1oF of average across the state. A few isolated spots in northern and southern Mohave, southwestern Maricopa, and

western Pima counties have been 2-4oF cooler than average. Maximum temperatures have also been within 1oF of average across most of Arizona with

slightly warmer than normal conditions in northern Arizona and cooler conditions in southern Arizona. Water Year precipitation has been 100 to 300% of

average in most of the state except Coconino and northern Navajo counties.

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April Mean Temperature Graphs – Flagstaff, Phoenix, and Tucson 1895-2020:

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April Precipitation Graphs – Flagstaff, Phoenix, and Tucson 1895-2020

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2020 Cumulative Precipitation Graphs – Flagstaff, Phoenix and Tucson:

Flagstaff is 1.10” below normal, Phoenix is 0.45” above normal, and Tucson is 0.75” below normal.

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The downloadable normals and extremes calendars use the following abbreviations:

NORM = 30 year (1971-2000) average value (degrees Fahrenheit (F))

OBS = The temperature observation for that day this year

AVG = Average daily temperature

HI MAX = Highest maximum temperature for that day (F)

LO MAX = Lowest maximum temperature for that day (F)

LO MIN = Lowest minimum temperature for that day (F)

HI MIN = Highest minimum temperature for that day (F)

Mx PCP = Maximum precipitation for that day (inches)

Mx SNO = Maximum snowfall for that day (inches)

arizona climate summary1 arizona climate summary may 2020 summary of conditions for april 2020 april...

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