Arco climate

Arco Weather in September

NOAA 1991-2020 normals for Arco, 0.2 km from Arco

Average highs run from 80°F on September 1 to 69°F on September 30, and lows from 45°F to 36°F. Normal precipitation for the month is 0.66 in over about 4 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 Arco, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
75°F
Average low
41°F
Precipitation
0.66 in
Record high
96°FSep 5, 2020
Record low
26°FSep 30, 2019
Chance of a freeze
72%
Days of 90°F or more
0.5
Daylight
13 h 11 min to 11 h 46 min
Cloud cover
40%
Humidity
39%
Dew point
29°F
Wind
7.4 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 180°F45°F94°F 202234°F 202011%0%
Sep 280°F45°F92°F 201741°F 201411%0%
Sep 380°F45°F95°F 201740°F 201411%0%
Sep 479°F44°F93°F 202238°F 201411%0%
Sep 579°F44°F96°F 202037°F 201611%0%
Sep 679°F44°F96°F 202233°F 201511%0%
Sep 778°F44°F96°F 202237°F 201511%0%
Sep 878°F43°F95°F 202240°F 202012%0%
Sep 978°F43°F92°F 202134°F 202012%0%
Sep 1077°F43°F89°F 201539°F 201612%0%
Sep 1177°F42°F86°F 201534°F 201412%0%
Sep 1277°F42°F88°F 201533°F 201412%0%
Sep 1376°F42°F86°F 201536°F 201612%0%
Sep 1476°F42°F87°F 202036°F 202612%0%
Sep 1575°F41°F84°F 201438°F 202612%0%
Sep 1675°F41°F86°F 201432°F 201812%0%
Sep 1775°F41°F87°F 201437°F 201812%0%
Sep 1874°F40°F83°F 202335°F 201512%0%
Sep 1974°F40°F80°F 201436°F 201712%0%
Sep 2073°F40°F83°F 202533°F 202112%0%
Sep 2173°F39°F80°F 201534°F 202112%0%
Sep 2273°F39°F82°F 201537°F 201912%0%
Sep 2372°F39°F80°F 201531°F 201712%0%
Sep 2472°F39°F85°F 201435°F 201712%0%
Sep 2571°F38°F86°F 201534°F 201812%0%
Sep 2671°F38°F84°F 202436°F 201812%0%
Sep 2770°F38°F83°F 202234°F 202012%0%
Sep 2870°F37°F87°F 202434°F 202012%0%
Sep 2969°F37°F86°F 202429°F 202112%0%
Sep 3069°F36°F79°F 201526°F 201912%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Arco, in percent, and of at least 0.1 inch of snowfall.02.557.51012.51102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (MDT).

September 1
sunrise 6:57 AM, sunset 8:08 PM
September 30
sunrise 7:30 AM, sunset 7:16 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00100375 (Arco), public domain. Records: NOAA GHCN-Daily, station USC00100774, 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.