October 2015 Temperature and Precipitation Summary Arizona Climate Summary November 2015 Summary of conditions for October 2015 October 1 st 14 th : October began with high pressure over the southwest, but a strong low pressure system was moving south along the California coast. High temperature on the 1 st was 106 o F at Phoenix, with 105 o F at Eloy and Bullhead City. The high on the 2 nd was 104 o F at Bullhead City. No rain fell in the state on the first 3 days of October, but temperatures fell as the low pressure system moved closer. Nighttime low temperatures dropped to 29 o F on the 3 rd in Flagstaff and the Grand Canyon Airport. On the 4 th the low pressure system reached southern California and rain fell in northern and central Arizona, with 0.25: at Sedona, 0.19 at Flagstaff, 0.16 at the Grand Canyon, and even 0.02 at Phoenix. The low pressure system moved through on the 5 th, 6 th and 7 th, finally pushing out to the northeast on the 8 th. Highs statewide remained below 100 o F from the 3 rd through the 8 th as the cold front passed. The highest rainfall total was 1.20 in Payson on the 5 th. Totals for the 5 days include 0.25 in Phoenix, 0.60 at Prescott, 1.43 at the Grand Canyon Airport, 1.58 at the north rim of the Grand Canyon, 1.22 at Flagstaff, 1.01 at Winslow, and 0.74 at Carefree. The state remained dry from the 10 th through the 14 th as high pressure returned to the southwest. October 15 th 31 st : Rain or snow fell in Arizona from the 15 th through the 23 rd as a strong slow moving low pressure system moved down the coast through California and across Arizona. The cold front brought daytime temperatures in the southwest deserts down into the 70s and upper 60s, with nighttime temperatures dropping into the 50s and upper 40s. Prescott had 0.2 of snow on the 16 th, and the higher elevations in the San Francisco Peaks and White Mountains also had snow. Rainfall totals included 0.75 at Carefree on the 16 th, 1.19 at Bellemont on the 17 th, 0.51 at Bisbee on the 18 th, 0.32 at Phoenix on the 19 th, 1.05 at Carefree and Bullhead City on the 20 th, 0.90 at Tucson on the 21 st, 0.41 at Bisbee on the 22 nd, and 0.25 at the Grand Canyon North Rim on the 23 rd. The 24 th through the 28 th were dry statewide, with the exception of 0.08 of rain at Alpine in the White Mountains on the 26 th. Daytime temperatures rebounded into the upper 80s and lower 90s in the southwest deserts and along the lower Colorado River as high pressure returned, while nighttime temperatures dropped into the upper 20s at the higher elevations. The month ended with one more low pressure system that moved quickly through the state bringing snow and rain on the 29 th, 30 th and 31 st. Rain totals included 0.69 at Eloy on the 29 th, 0.31 at the Petrified Forest on the 30 th, and 0.50 at Douglas on the 31 st. 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. In This Issue: Overview of October, graphs of the October daily maximum and minimum temperatures, precipitation, mean daily dew points for Flagstaff, Phoenix, and Tucson; October climate statistics, maps of mean monthly maximum and minimum temperatures, precipitation, dew points, wind speeds for October; and graphs of the mean October 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. Climate calendars for Flagstaff, Phoenix, Tucson, Prescott, Winslow and Yuma, including daily and monthly normals and extremes, for each month of the year, can be downloaded directly from the State Climate website. See p.19 of this report for calendar abbreviations. Dr. Nancy J. Selover, State Climatologist http://azclimate.asu.edu 480-965-6265 Edited by Nancy J. Selover & Kira Frost 2015 Arizona State Climate Office 1
October 2015 Daily Temperature, Precipitation, & Dew Point for Flagstaff, Phoenix, and Tucson 2
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FLAGSTAFF CLIMATE STATISTICS October 2015 This October was tied for 19 th warmest with 1937 and 1960 and was the 9 th wettest. Avg Max Temp (F) 63.0 Normal 62.0 Avg Min Temp (F) 36.7 Normal 31.5 Avg Mean Temp (F) 49.9 Normal 46.8 Departure from Normal (F) +3.1 Highest Monthly Avg Temp (F) 52.5 in 1988 Lowest Monthly Avg Temp (F) 38.6 in 1971 Highest Temp this month (F): 78 on 14 th Lowest Temp this month (F): 28 on 31 th Record High (F): 85 on 10/01/1980 Record Low (F): -2.0 on 10/30/1971 Temperature or precipitation records this month: 14 th HiMax 78 tied, first set in 1991 16 th HiMin 49 set, previous record 44 set in 1972 17 th HiMin 44 tied, first set in 2004 Maximum Temp 70 o F or higher 7 Maximum Temp 50 o F or lower 2 Heating Degree Days 465 Normal 566 Cooling Degree Days 0 Normal 0 Degree base 65 o F Total October Precipitation 3.72 Normal October Precipitation 1.66 Departure from normal +2.06 Greatest 24-Hr Precipitation 1.08 on 16-17 th Total Precipitation Year-to-Date 23.39 Departure from Normal +5.16 Number of Days: Clear 18 Partly Cloudy 11 Cloudy 2 Greatest October Precipitation 9.89 in 1972 Least October Precipitation 0.00 in 1917, 1902 Flagstaff Number of Days of: Minimum Temp 40 o F or higher 10 Minimum Temp 32 o F or lower 8 Average Wind Speed Highest Peak Gust 5.5 mph 41mph from 030 o on 30 th PHOENIX CLIMATE STATISTICS October 2015 This October was tied with 2001 as the 7 th warmest and had no significant ranking for precipitation. Avg Max Temp(F) 90.0 Normal 88.5 Avg Min Temp(F) 68.8 Normal 64.8 Avg Mean Temp (F) 79.4 Normal 76.7 Departure from Normal (F) +2.7 Highest Monthly Avg Temp (F) 82.7 in 2003 Lowest Monthly Avg Temp (F) 66.1 in 1916 Highest Temp this month (F): Lowest Temp this month (F): 106 on 1st 57 on 31st Record High (F): 107 on 10/02/1980, 10/01/1980 Record Low (F): 34 on 10/30/1971 13 th HiMin 75 tied, first set in 2003 14 th HiMax 100 tied, first set in 2010 14 th HiMin 76 set, previous record 75 in 2010 15 th HiMin 76 set, previous record 72 in2010 16 th HiMin 74 set, previous record 73 in 2003 17 th HiMin 72 tied, first set in 2009 Phoenix Number of Days of: Minimum Temp 60 o F or lower 2 Minimum Temp 75 o F or higher 6 Maximum Temp 80 o F or lower 3 Maximum Temp 100 o F or higher 2 Heating Degree Days 0 Normal 6 Cooling Degree Days 455 Normal 367 Degree base 65 o F Temperature or precipitation records this month: 4
Total October Precipitation 0.71 Normal October Precipitation 0.58 Departure from normal +0.13 Greatest 24-Hr Precipitation 0.34 10/17-10/18 Total Precipitation Year-to-Date 6.69 Departure from Normal +0.19 Greatest October Precipitation 4.40 in 1972 Least October Precipitation 0.00 in 1973, 1995, and 1999 Average Wind Speed 5.9 mph Highest Peak Gust 44 mph from 300 o on 20 th Number of Days: Clear 12 Partly Cloudy 18 Cloudy 1 TUCSON CLIMATE STATISTICS October 2015 This October was the 13 th warmest and 8 th wettest. Avg Max Temp(F) 85.3 Normal 84.8 Avg Min Temp(F) 61.9 Normal 57.3 Avg Mean Temp(F) 73.6 Normal 71.0 Departure from Normal (F) +2.6 Highest Monthly Avg Temp (F) 76.8 in 1950 Lowest Monthly Avg Temp (F) 63.1 in 1920 Highest Temp this month (F): 101 on 1 st Lowest Temp this month (F): 49 on 31 st Record High (F): 102 on 10/01/2010, 10/03/1993 Record Low (F): 26 on 10/30/1971 Temperature or precipitation records this month: 15 th HiMin 68 tied, first set in 1918 25 th HiMin 66 set, previous record 64 in 1998 Tucson Number of Days of: Minimum Temp 60 o F or lower 12 Minimum Temp 70 o F or higher 4 Maximum Temp 75 o F or lower 3 Maximum Temp 90 o F or higher 9 Heating Degree Days 10 Normal 24 Cooling Degree Days 284 Normal 212 Degree base 65 o F Total October Precipitation 2.25 Normal October Precipitation 0.89 Departure from normal +1.36 Greatest 24-Hr Precipitation 0.91 on 20-21 Total Precipitation Year-to-Date 12.79 Departure from Normal +2.70 Greatest October Precipitation 4.98 in 2000 Least October Precipitation 0.00 in 2013, 1999,1982,1975 and 14 other years Number of Days: Clear 22 Partly Cloudy 9 Cloudy 0 Average Wind Speed Highest Peak Gust 7.3 mph 46 mph from 250 o on 6 th Data are from the National Weather Service and the National Climatic Data Center and are preliminary. 5
Wind Speeds for May: Day Phoenix Flagstaff Tucson (mph) Avg Max Avg Max Avg Max 1 7.4 21 10.2 40 5.7 19 2 6.9 M 10.1 39 9.6 30 3 4.9 16 5.8 25 8.2 28 4 12.1 34 4.5 25 10.8 32 5 10.1 32 6.6 35 10.4 34 6 6.4 36 4.7 21 6.7 46 7 3.7 17 6 26 3 22 8 3.7 15 10.7 32 4.2 19 9 7.7 27 6 29 10.9 37 10 4.4 16 3.3 19 8.2 25 11 4.9 15 3.4 18 4.8 15 12 3.8 19 3.9 20 3.2 13 13 4.3 17 2.3 19 4.7 20 14 4.4 15 2.4 17 4.7 16 15 5.9 17 3.3 19 10.3 36 16 9.2 39 6 28 11.9 31 17 9 26 3.2 26 15.1 39 18 7 32 6.9 26 9.1 31 19 4.1 16 9.4 31 5.5 20 20 6.8 44 4.5 27 6.1 31 21 6.1 20 6.5 18 4.6 28 22 3.9 12 3 16 4.3 16 23 3.7 17 5.3 20 6 22 24 4.9 19 4.6 20 7.7 25 25 5.3 18 2.5 17 9.7 30 26 3.5 16 3.3 19 5 20 27 4.2 14 4.9 24 6 19 28 5 14 4.2 33 7.5 19 29 9.1 32 4.5 25 10.4 34 30 5 21 14.2 41 5.8 29 31 4 13 4.9 33 4.7 14 Dew Points for May: Daily Average Dew Point ( o F): Day Phx Tuc Flg 1 44 45 33 2 38 45 26 3 46 50 36 4 51 52 43 5 58 55 46 6 56 53 43 7 56 51 41 8 53 49 41 9 52 51 41 10 52 51 39 11 54 54 36 12 54 54 32 13 54 51 28 14 50 49 30 15 53 49 39 16 56 55 43 17 60 58 49 18 61 58 47 19 60 54 44 20 55 52 40 21 51 51 38 22 52 50 38 23 48 46 37 24 48 48 36 25 48 46 36 26 46 47 28 27 45 43 27 28 47 45 33 29 48 47 34 30 42 46 31 31 39 50 19 6
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The lowest minimum temperatures ranged from 10 o F at Colorado City near the Utah Border to 59 o F at Yuma. The lowest maximum temperature of 62 o F was recorded at Snowslide Canyon, while the highest maximum temperature of 110 o F was reported at Alamo Dam. The lowest rainfall amount was 0.00 at several stations in the Yuma area and the highest were 5.80 at Mormon Mountain and 6.20 at Snowslide Canyon. The lowest average dew point was 34 o F at Window Rock and the highest was 57 o F at Paloma. The highest peak wind gust was 54 mph at San Simon. 8
T October 2015 The highest average minimum temperature was 71 o F at Yuma and the lowest average minimum temperature was 33 o F at Sunrise Mountain. The highest average maximum temperature was 95 o F at Yuma and lowest average maximum temperature was 51 o F at Snowslide Canyon. 9
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October October minimum temperatures were 2 to 8 o F warmer than average across the state, with the warmest conditions along the western counties. Daytime temperatures were within 1 o F of normal in central Arizona, and 1 to 3 o F warmer than normal toward the western, eastern and northern borders. Western Maricopa County was cooler than normal due to a strong storm system that stalled over that area in October. October precipitation was well above normal across most of the state with near normal rainfall in Greenlee County, western Pinal, eastern Cochise and Graham counties, and central Apache County. 11
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Calendar Year 2015 Calendar year minimum temperatures continued to be 0 to 4 o F warmer than average across most of the state, with the warmest conditions in central Gila County. Daytime temperatures were also about 0 to 3 o F warmer than average across northern and western Arizona, and 0 to 1.5 o F warmer than average across the southeastern counties. Western Pinal County was cooler than normal. Precipitation has been much above normal across the Colorado Plateau as well as in northern Mohave and eastern Pinal counties. Maricopa County was slightly drier than normal. 13
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2016 Water Year The water year began with minimum temperatures 2 to 8 o F warmer than average across the state, with the warmest conditions along the western counties. Daytime temperatures were within 1 o F of normal in central Arizona, and 1 to 3 o F warmer than normal toward the western, eastern and northern borders. Western Maricopa County was cooler than normal due to a strong storm system that stalled over that area in October. Precipitation was well above normal across most of the state with near normal rainfall in Greenlee County, western Pinal, eastern Cochise and Graham counties, and central Apache County. 15
October Mean Temperature Graphs Flagstaff, Phoenix, and Tucson 1895-2015: 16
October Mean Precipitation Graphs Flagstaff, Phoenix, and Tucson 1895-2015: 17
2015 Cumulative Precipitation Graphs Flagstaff, Phoenix and Tucson: Flagstaff is 5.16 wetter than normal, Tucson is 2.70 wetter than normal and Phoenix is 0.17 wetter than normal. 18
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) 19