Riley climate

Riley Weather in September

NOAA 1991-2020 normals for Manhattan, 24.3 km from Riley

Average highs run from 86°F on September 1 to 76°F on September 30, and lows from 62°F to 51°F. Normal precipitation for the month is 3.41 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 Riley, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
81°F
Average low
57°F
Precipitation
3.41 in
Record high
111°FSep 2, 2000
Record low
31°FSep 21, 1999
Chance of a freeze
9%
Days of 90°F or more
7.4
Daylight
13 h 02 min to 11 h 48 min
Cloud cover
45%
Humidity
64%
Dew point
54°F
Wind
10.5 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 186°F62°F109°F 201152°F 200929%0%
Sep 286°F62°F111°F 200053°F 200329%0%
Sep 385°F62°F105°F 200049°F 200629%0%
Sep 485°F61°F101°F 202347°F 201029%0%
Sep 585°F61°F101°F 202645°F 200829%0%
Sep 684°F61°F101°F 199842°F 201129%0%
Sep 784°F60°F103°F 201343°F 201129%0%
Sep 884°F60°F105°F 202644°F 201129%0%
Sep 984°F60°F98°F 201344°F 199929%0%
Sep 1083°F59°F102°F 200041°F 196229%0%
Sep 1183°F59°F96°F 196345°F 200729%0%
Sep 1283°F59°F96°F 201139°F 201429%0%
Sep 1382°F58°F100°F 200035°F 201429%0%
Sep 1482°F58°F98°F 202640°F 196129%0%
Sep 1582°F58°F96°F 201936°F 196129%0%
Sep 1681°F57°F94°F 200639°F 199929%0%
Sep 1781°F57°F97°F 200046°F 202329%0%
Sep 1881°F56°F100°F 202241°F 200329%0%
Sep 1980°F56°F101°F 202236°F 200329%0%
Sep 2080°F56°F101°F 202237°F 199929%0%
Sep 2180°F55°F97°F 201731°F 199929%0%
Sep 2279°F55°F97°F 201735°F 199929%0%
Sep 2379°F54°F94°F 201737°F 201229%0%
Sep 2479°F54°F93°F 201741°F 200128%0%
Sep 2578°F53°F93°F 199837°F 200128%0%
Sep 2678°F53°F98°F 202135°F 200028%0%
Sep 2777°F53°F96°F 202136°F 196428%0%
Sep 2877°F52°F98°F 202334°F 196428%0%
Sep 2977°F52°F97°F 202335°F 200928%0%
Sep 3076°F51°F96°F 202335°F 200328%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Riley, 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 (CDT).

September 1
sunrise 6:56 AM, sunset 7:58 PM
September 30
sunrise 7:23 AM, sunset 7:11 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00144972 (Manhattan), public domain. Records: NOAA GHCN-Daily, station USW00003936, 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.