Keene weather in September

In September, Keene sees average daytime highs of 71°F and overnight lows near 51°F, with 3.4 in of rain across 8.6 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 75°F in the first days to 65°F by the end. The sky is clear or mostly clear about 36% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Keene's 1st-clearest and 10th-windiest month. For the whole year in context, see Keene's year-round climate.

Daytime high
71°
4th warmest
Overnight low
51°
9th coldest
Rainfall
3.4 in
8.6 wet days
Daylight
12 h 18 min
5:35 AM – 5:52 PM
Cloud cover
57%
1st clearest
Wind
6 mph
10th windiest
Solar energy
4.11 kWh/m²
Travel score
6.7
out of 10

Keene is city in New Hampshire, United States.

Density
240/km²
people per km²
Founded
1736

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 75°F in the first days to 65°F by the end.

A typical September day in Keene reaches about 71°F in the afternoon and slips back to 51°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 61°F and 81°F. Set against its neighbours, September runs about 8°F cooler than August and about 13°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17656
27555
37555
47555
57455
67454
77454
87354
97353
107353
117253
127252
137252
147152
157151
167051
177051
187050
196950
206949
216849
226849
236848
246748
256748
266647
276647
286547
296546
306446

How September really feels in Keene

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Keene weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan30° / 14°3.19.57.19.20.0
Feb33° / 15°2.98.7710.20.0
Mar41° / 24°3.710.76.211.60.3
Apr54° / 36°3.6112.413.13.2
May65° / 46°3.111.30.114.45.6
Jun75° / 55°3.411.9015.16.4
Jul80° / 61°3.310014.86.5
Aug78° / 59°3.29.5013.86.8
Sep71° / 51°3.48.6012.36.7
Oct58° / 40°4.09.60.510.84.3
Nov46° / 31°3.39.62.59.51.1
Dec35° / 21°4.010.16.28.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 49%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15347
25347
35248
45248
55149
65149
75149
85248
95248
105248
115248
125248
135248
145248
155248
165149
175149
185149
195149
205050
215050
225050
234951
244951
254852
264951
274951
284852
294852
305050

Chance of precipitation in September

Any precipitation

Keene gets around 3.4 in of rain over 8.6 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 29% and peaks near 31% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
125
225
326
426
527
627
727
828
928
1029
1129
1229
1329
1429
1529
1629
1729
1829
1929
2029
2129
2230
2330
2430
2530
2630
2731
2831
2931
3031

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 65% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
15125177
25125177
35224177
45324167
55423167
65423167
75622166
85622166
95721166
105821165
115920165
125920165
136119164
146318154
156318154
166517153
176616153
186815143
196815143
207114132
217114132
227313122
237313122
247612111
257712101
26781291
27801181
28801181
29811171
30821161

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 5:18 AM to 5:51 AM, and sunset from 6:20 PM to 5:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:186:20
213.05:196:18
312.95:206:16
412.95:216:14
512.85:226:12
612.85:246:11
712.75:256:09
812.75:266:07
912.65:276:05
1012.65:286:03
1112.55:296:01
1212.55:306:00
1312.45:315:58
1412.45:335:56
1512.35:345:54
1612.35:355:52
1712.25:365:50
1812.25:375:48
1912.15:385:46
2012.15:395:45
2112.05:405:43
2212.05:425:41
2311.95:435:39
2411.95:445:37
2511.85:455:35
2611.85:465:33
2711.75:475:32
2811.75:485:30
2911.65:505:28
3011.65:515:26

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.11 kWh/m².

For context, solar energy here swings from a low near 1.53 kWh/m² to a high of 5.91 kWh/m² in July across the year — September's 4.11 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.6Bright
54.6Bright
64.5Bright
74.5Bright
84.4Bright
94.4Bright
104.4Bright
114.3Bright
124.3Bright
134.2Bright
144.2Bright
154.2Bright
164.1Bright
174.1Bright
184.0Bright
194.0Moderate
203.9Moderate
213.9Moderate
223.8Moderate
233.8Moderate
243.7Moderate
253.7Moderate
263.6Moderate
273.6Moderate
283.5Moderate
293.5Moderate
303.4Moderate
Planning a trip in September

Is September a good time to visit Keene?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.7
Sightseeing
2nd-best month of the year
4.3
Beach & pool
4th-best month of the year

September is a reasonable time to visit Keene for sightseeing.

What to pack for Keene in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Keene sees daytime highs around 71°F and nights near 51°F. Worth packing: rain gear. About 9 days see rain.

rain gear

UV index in Keene in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Keene peaks around July 12 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 12UV 7Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb3Moderate
Mar4Moderate
Apr5High
May7Very high
Jun7High
Jul8Very high
Aug5Moderate
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low
Location & terrain

Where is Keene?

Keene sits at 42.9°N, 72.3°W, 486 ft above sea level, in United States. The nearest listed city is Gardner, 29 mi away.

Topography around Keene

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Keene.

Within 2 miles, the terrain around Keene has only modest variations in elevation — a maximum elevation change of 610 ft around an average of 600 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,910 ft; within 50 miles, large variations in elevation — a maximum elevation change of 3,855 ft.

The land around Keene is covered by trees (71%) within 2 miles, trees (91%) within 10 miles, and trees (93%) within 50 miles.

2 miles
610 ft
10 miles
2,910 ft
50 miles
3,855 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Gardner 29 mi · Greenfield 29 mi · Fitchburg 34 mi · Bedford 39 mi · Leominster 39 mi · Merrimack 40 mi · Amherst Center 40 mi · Amherst 41 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Keene (42.9337°, -72.2781°, elevation 486 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).