Cornelius climate

Cornelius Weather in September

NOAA 1991-2020 normals for Forest Grove, 3.4 km from Cornelius

Average highs run from 80°F on September 1 to 71°F on September 30, and lows from 51°F to 46°F. Normal precipitation for the month is 1.34 in over about 5 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 Cornelius, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
76°F
Average low
49°F
Precipitation
1.34 in
Record high
100°FSep 2, 2017
Record low
30°FSep 27, 1999
Chance of a freeze
2%
Days of 90°F or more
3.4
Daylight
13 h 16 min to 11 h 45 min
Cloud cover
49%
Humidity
76%
Dew point
51°F
Wind
4.5 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 180°F51°F96°F 201738°F 199914%0%
Sep 280°F51°F100°F 201740°F 201214%0%
Sep 379°F51°F98°F 202042°F 199915%0%
Sep 479°F51°F95°F 200339°F 201515%0%
Sep 579°F51°F100°F 202440°F 200015%0%
Sep 679°F51°F95°F 201438°F 200116%0%
Sep 779°F50°F96°F 201137°F 199916%0%
Sep 878°F50°F90°F 201138°F 200216%0%
Sep 978°F50°F93°F 201139°F 200017%0%
Sep 1078°F50°F95°F 201138°F 199917%0%
Sep 1178°F50°F97°F 201337°F 201218%0%
Sep 1277°F50°F90°F 201542°F 201218%0%
Sep 1377°F49°F92°F 199941°F 200818%0%
Sep 1477°F49°F92°F 202342°F 201419%0%
Sep 1577°F49°F94°F 202340°F 201519%0%
Sep 1676°F49°F90°F 200837°F 202120%0%
Sep 1776°F49°F91°F 201241°F 201820%0%
Sep 1876°F48°F91°F 199936°F 200720%0%
Sep 1975°F48°F92°F 199939°F 200721%0%
Sep 2075°F48°F93°F 201436°F 200121%0%
Sep 2175°F48°F88°F 199939°F 200222%0%
Sep 2274°F47°F92°F 200935°F 200522%0%
Sep 2374°F47°F88°F 200235°F 200023%0%
Sep 2474°F47°F91°F 202432°F 200023%0%
Sep 2573°F47°F90°F 202235°F 200024%0%
Sep 2673°F47°F90°F 201635°F 200024%0%
Sep 2773°F46°F95°F 200330°F 199925%0%
Sep 2872°F46°F86°F 200633°F 199925%0%
Sep 2972°F46°F89°F 200835°F 200726%0%
Sep 3071°F46°F85°F 201034°F 201927%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Cornelius, 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 (PDT).

September 1
sunrise 6:34 AM, sunset 7:50 PM
September 30
sunrise 7:09 AM, sunset 6:54 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00352997 (Forest Grove), public domain. Records: NOAA GHCN-Daily, station USW00094261, 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.