Delta County climate

Delta County Weather in September

NOAA 1991-2020 normals for Cooper Dam, 9.8 km from Delta County

Average highs run from 91°F on September 1 to 84°F on September 30, and lows from 69°F to 61°F. Normal precipitation for the month is 3.25 in over about 7 wet days.

September day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Delta County, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
88°F
Average low
65°F
Precipitation
3.25 in
Record high
112°FSep 4, 2000
Record low
39°FSep 30, 1949
Chance of a freeze
0%
Days of 90°F or more
16.2
Daylight
12 h 51 min to 11 h 52 min
Cloud cover
43%
Humidity
63%
Dew point
62°F
Wind
7.6 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Sep 191°F69°F109°F 200053°F 189323%0%
Sep 291°F69°F110°F 200054°F 196523%0%
Sep 391°F69°F111°F 200054°F 197423%0%
Sep 491°F68°F112°F 200047°F 197423%0%
Sep 591°F68°F112°F 200049°F 197423%0%
Sep 690°F68°F104°F 189650°F 197422%0%
Sep 790°F68°F105°F 189651°F 201122%0%
Sep 890°F67°F105°F 202351°F 197422%0%
Sep 990°F67°F104°F 189551°F 200422%0%
Sep 1090°F67°F104°F 189551°F 202422%0%
Sep 1189°F67°F106°F 189548°F 194822%0%
Sep 1289°F66°F108°F 189551°F 194822%0%
Sep 1389°F66°F108°F 189546°F 190222%0%
Sep 1489°F66°F106°F 189345°F 190222%0%
Sep 1588°F65°F106°F 189346°F 190222%0%
Sep 1688°F65°F108°F 189345°F 197922%0%
Sep 1788°F65°F105°F 189343°F 190322%0%
Sep 1888°F65°F103°F 189344°F 198122%0%
Sep 1987°F64°F103°F 189341°F 198122%0%
Sep 2087°F64°F106°F 189347°F 199122%0%
Sep 2187°F64°F102°F 189542°F 198322%0%
Sep 2287°F63°F103°F 189340°F 198322%0%
Sep 2386°F63°F104°F 189344°F 199422%0%
Sep 2486°F63°F101°F 189340°F 198922%0%
Sep 2586°F62°F100°F 189540°F 198922%0%
Sep 2686°F62°F103°F 189542°F 200022%0%
Sep 2785°F62°F101°F 195440°F 198222%0%
Sep 2885°F61°F99°F 189741°F 190922%0%
Sep 2985°F61°F103°F 195340°F 196722%0%
Sep 3084°F61°F102°F 189339°F 194922%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Delta County, in percent, and of at least 0.1 inch of snowfall.05101520251102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (CDT).

September 1
sunrise 6:57 AM, sunset 7:48 PM
September 30
sunrise 7:16 AM, sunset 7:08 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00411968 (Cooper Dam), public domain. Records: NOAA GHCN-Daily, station USC00418743, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.