Delta climate

Delta Weather in September

NOAA 1991-2020 normals for Conowingo Dam, 15.2 km from Delta

Average highs run from 83°F on September 1 to 74°F on September 30, and lows from 64°F to 55°F. Normal precipitation for the month is 5.05 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 Delta, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
79°F
Average low
60°F
Precipitation
5.05 in
Record high
99°FSep 3, 1993
Record low
32°FSep 27, 1991
Chance of a freeze
0%
Days of 90°F or more
2.5
Daylight
13 h 03 min to 11 h 48 min
Cloud cover
55%
Humidity
72%
Dew point
58°F
Wind
6.9 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 183°F64°F97°F 201051°F 193627%0%
Sep 283°F64°F96°F 195340°F 200227%0%
Sep 383°F64°F99°F 199340°F 200227%0%
Sep 483°F64°F95°F 198547°F 198727%0%
Sep 582°F63°F95°F 198549°F 198727%0%
Sep 682°F63°F97°F 198347°F 195727%0%
Sep 782°F63°F94°F 198341°F 198828%0%
Sep 881°F63°F96°F 193945°F 196228%0%
Sep 981°F62°F93°F 198543°F 198628%0%
Sep 1081°F62°F99°F 200242°F 194928%0%
Sep 1181°F62°F98°F 198343°F 201728%0%
Sep 1280°F61°F92°F 198340°F 201728%0%
Sep 1380°F61°F92°F 195240°F 195428%0%
Sep 1480°F61°F90°F 197241°F 195328%0%
Sep 1579°F60°F92°F 199539°F 196428%0%
Sep 1679°F60°F93°F 199840°F 198828%0%
Sep 1779°F60°F96°F 199143°F 198428%0%
Sep 1878°F59°F90°F 200239°F 193729%0%
Sep 1978°F59°F93°F 198338°F 199029%0%
Sep 2078°F59°F91°F 198340°F 197929%0%
Sep 2177°F58°F90°F 194035°F 195629%0%
Sep 2277°F58°F95°F 197035°F 199129%0%
Sep 2376°F58°F91°F 197040°F 196329%0%
Sep 2476°F57°F92°F 196134°F 196329%0%
Sep 2576°F57°F90°F 197035°F 196330%0%
Sep 2675°F57°F90°F 201039°F 199030%0%
Sep 2775°F56°F94°F 199832°F 199130%0%
Sep 2874°F56°F89°F 200735°F 195730%0%
Sep 2974°F55°F84°F 195436°F 197830%0%
Sep 3074°F55°F90°F 198634°F 195130%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Delta, 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 6:33 AM, sunset 7:36 PM
September 30
sunrise 7:01 AM, sunset 6:49 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00182060 (Conowingo Dam), public domain. Records: NOAA GHCN-Daily, station USC00182060, 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.