Hyannis Weather in September
Average highs run from 81°F on September 1 to 68°F on September 30, and lows from 54°F to 43°F. Normal precipitation for the month is 1.61 in over about 7 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 75°F
- Average low
- 49°F
- Precipitation
- 1.61 in
- Record high
- 103°FSep 5, 2020
- Record low
- 21°FSep 29, 1999
- Chance of a freeze
- 24%
- Days of 90°F or more
- 2.4
- Daylight
- 13 h 07 min to 11 h 47 min
- Cloud cover
- 46%
- Humidity
- 53%
- Dew point
- 43°F
- Wind
- 11.2 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Sep 1 | 81°F | 54°F | 100°F 2023 | 35°F 2005 | 24% |
| Sep 2 | 81°F | 54°F | 99°F 2023 | 31°F 2006 | 24% |
| Sep 3 | 80°F | 54°F | 98°F 1998 | 31°F 2010 | 24% |
| Sep 4 | 80°F | 53°F | 101°F 1998 | 32°F 2011 | 24% |
| Sep 5 | 80°F | 53°F | 103°F 2020 | 34°F 2017 | 25% |
| Sep 6 | 80°F | 53°F | 101°F 2022 | 28°F 2025 | 25% |
| Sep 7 | 79°F | 52°F | 102°F 2022 | 29°F 2010 | 25% |
| Sep 8 | 79°F | 52°F | 96°F 2005 | 32°F 2020 | 25% |
| Sep 9 | 78°F | 52°F | 97°F 2024 | 31°F 2001 | 25% |
| Sep 10 | 78°F | 51°F | 99°F 2012 | 27°F 2020 | 25% |
| Sep 11 | 78°F | 51°F | 96°F 2021 | 31°F 2016 | 25% |
| Sep 12 | 77°F | 51°F | 95°F 2004 | 31°F 2014 | 25% |
| Sep 13 | 77°F | 50°F | 95°F 2015 | 30°F 1999 | 25% |
| Sep 14 | 76°F | 50°F | 94°F 2015 | 33°F 2012 | 25% |
| Sep 15 | 76°F | 50°F | 96°F 2018 | 32°F 2003 | 25% |
| Sep 16 | 76°F | 49°F | 96°F 2000 | 35°F 2006 | 26% |
| Sep 17 | 75°F | 49°F | 100°F 2000 | 31°F 2006 | 26% |
| Sep 18 | 75°F | 48°F | 94°F 1998 | 32°F 2003 | 26% |
| Sep 19 | 74°F | 48°F | 93°F 2022 | 30°F 2006 | 26% |
| Sep 20 | 74°F | 48°F | 92°F 2007 | 31°F 2011 | 26% |
| Sep 21 | 73°F | 47°F | 94°F 2005 | 26°F 2011 | 26% |
| Sep 22 | 73°F | 47°F | 92°F 2020 | 26°F 2002 | 26% |
| Sep 23 | 72°F | 46°F | 94°F 2007 | 31°F 2011 | 26% |
| Sep 24 | 72°F | 46°F | 91°F 2020 | 29°F 2000 | 26% |
| Sep 25 | 71°F | 45°F | 90°F 2014 | 26°F 2000 | 26% |
| Sep 26 | 70°F | 45°F | 97°F 2024 | 25°F 2018 | 25% |
| Sep 27 | 70°F | 45°F | 93°F 2021 | 27°F 2006 | 25% |
| Sep 28 | 69°F | 44°F | 94°F 2024 | 22°F 2006 | 25% |
| Sep 29 | 69°F | 44°F | 93°F 2024 | 21°F 1999 | 25% |
| Sep 30 | 68°F | 43°F | 88°F 2005 | 29°F 2024 | 25% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (MDT).
- September 1
- sunrise 6:13 AM, sunset 7:20 PM
- September 30
- sunrise 6:43 AM, sunset 6:30 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00094079 (Whitman 5 Ene), public domain. Records: NOAA GHCN-Daily, station USW00024044, 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.