Monticello climate

Monticello Weather in September

NOAA 1991-2020 normals for Monticello 2E, 3.1 km from Monticello

Average highs run from 80°F on September 1 to 69°F on September 30, and lows from 50°F to 39°F. Normal precipitation for the month is 1.67 in over about 8 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 Monticello, 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
45°F
Precipitation
1.67 in
Snowfall
0.1 in
Record high
93°FSep 7, 2022
Record low
29°FSep 9, 2020
Chance of a freeze
40%
Daylight
12 h 59 min to 11 h 50 min
Cloud cover
34%
Humidity
42%
Dew point
35°F
Wind
7.8 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°F50°F87°F 201946°F 201430%0%
Sep 280°F49°F90°F 201943°F 201830%0%
Sep 379°F49°F90°F 202248°F 201830%0%
Sep 479°F49°F90°F 201745°F 201630%0%
Sep 579°F49°F91°F 201740°F 201629%0%
Sep 679°F48°F91°F 202241°F 201629%0%
Sep 778°F48°F93°F 202241°F 201629%0%
Sep 878°F48°F89°F 202245°F 201629%0%
Sep 978°F47°F90°F 202229°F 202028%0%
Sep 1077°F47°F87°F 202131°F 202028%0%
Sep 1177°F47°F85°F 202133°F 202028%0%
Sep 1277°F46°F83°F 202637°F 201927%0%
Sep 1376°F46°F84°F 201539°F 201927%0%
Sep 1476°F45°F81°F 201537°F 202527%0%
Sep 1576°F45°F81°F 201936°F 201626%0%
Sep 1675°F45°F82°F 202143°F 201226%0%
Sep 1775°F44°F79°F 202042°F 201726%0%
Sep 1874°F44°F85°F 201836°F 202425%0%
Sep 1974°F44°F82°F 201840°F 202425%0%
Sep 2074°F43°F79°F 201641°F 201125%0%
Sep 2173°F43°F83°F 201440°F 201924%0%
Sep 2273°F42°F80°F 201537°F 202324%0%
Sep 2372°F42°F78°F 201236°F 201623%0%
Sep 2472°F42°F79°F 201233°F 201723%0%
Sep 2571°F41°F81°F 201532°F 201723%0%
Sep 2671°F41°F80°F 201434°F 201722%0%
Sep 2770°F40°F83°F 202436°F 201722%0%
Sep 2870°F40°F83°F 202431°F 201322%0%
Sep 2969°F40°F82°F 202430°F 201322%0%
Sep 3069°F39°F80°F 201135°F 201422%1%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Monticello, in percent, and of at least 0.1 inch of snowfall.0102030401102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (MDT).

September 1
sunrise 6:47 AM, sunset 7:46 PM
September 30
sunrise 7:12 AM, sunset 7:02 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00425805 (Monticello 2E), public domain. Records: NOAA GHCN-Daily, station USC00425807, 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.