Union County climate

Union County Weather in September

NOAA 1991-2020 normals for Marysville, 14.7 km from Union County

Average highs run from 82°F on September 1 to 72°F on September 30, and lows from 60°F to 49°F. Normal precipitation for the month is 3.20 in over about 9 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 Union County, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
78°F
Average low
55°F
Precipitation
3.20 in
Record high
102°FSep 2, 1953
Record low
27°FSep 29, 1942
Chance of a freeze
1%
Days of 90°F or more
1.9
Daylight
13 h 04 min to 11 h 48 min
Cloud cover
50%
Humidity
70%
Dew point
54°F
Wind
8.5 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 182°F60°F100°F 193241°F 194827%0%
Sep 282°F59°F102°F 195337°F 192427%0%
Sep 381°F59°F100°F 195339°F 194627%0%
Sep 481°F59°F95°F 195340°F 194627%0%
Sep 581°F58°F98°F 195439°F 191727%0%
Sep 681°F58°F98°F 195438°F 192427%0%
Sep 780°F58°F98°F 193936°F 192428%0%
Sep 880°F58°F98°F 193935°F 195128%0%
Sep 980°F57°F95°F 193940°F 194428%0%
Sep 1080°F57°F97°F 201338°F 192428%0%
Sep 1179°F57°F93°F 193132°F 191728%0%
Sep 1279°F56°F96°F 193134°F 191728%0%
Sep 1379°F56°F96°F 193136°F 195528%0%
Sep 1478°F55°F102°F 193930°F 192328%0%
Sep 1578°F55°F97°F 193932°F 192328%0%
Sep 1678°F55°F98°F 193934°F 196628%0%
Sep 1777°F54°F93°F 195535°F 193728%0%
Sep 1877°F54°F94°F 195533°F 195928%0%
Sep 1977°F54°F95°F 195534°F 192929%0%
Sep 2076°F53°F93°F 194034°F 193729%0%
Sep 2176°F53°F93°F 194029°F 195629%0%
Sep 2275°F52°F92°F 202431°F 191829%0%
Sep 2375°F52°F92°F 193031°F 196729%0%
Sep 2475°F52°F92°F 200732°F 195029%0%
Sep 2574°F51°F90°F 193932°F 194229%0%
Sep 2674°F51°F91°F 199831°F 192829%0%
Sep 2773°F51°F89°F 199830°F 194729%0%
Sep 2873°F50°F90°F 195931°F 194229%0%
Sep 2973°F50°F98°F 195327°F 194229%0%
Sep 3072°F49°F93°F 195331°F 193529%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Union County, in percent, and of at least 0.1 inch of snowfall.01020301102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (EDT).

September 1
sunrise 7:01 AM, sunset 8:05 PM
September 30
sunrise 7:29 AM, sunset 7:17 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00334979 (Marysville), public domain. Records: NOAA GHCN-Daily, station USC00334979, 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.