Jamestown weather in September

In September, Jamestown sees average daytime highs of 69°F and overnight lows near 47°F, with 2.5 in of rain across 7.4 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 74°F in the first days to 63°F by the end. The sky is clear or mostly clear about 43% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 12 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Jamestown's 3rd-clearest and 9th-windiest month. For the whole year in context, see Jamestown's year-round climate.

Daytime high
69°
4th warmest
Overnight low
47°
9th coldest
Rainfall
2.5 in
7.4 wet days
Daylight
12 h 18 min
6:19 AM – 6:39 PM
Cloud cover
49%
3rd clearest
Wind
10 mph
9th windiest
Solar energy
4.2 kWh/m²
Travel score
6.9
out of 10

Jamestown is seat of Stutsman County, North Dakota, United States.

Density
462/km²
people per km²
Founded
1872

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 74°F in the first days to 63°F by the end.

A typical September day in Jamestown reaches about 69°F in the afternoon and slips back to 47°F overnight — a 21°F spread between the day's warmth and the night's chill. On most days the high lands between 56°F and 82°F. Set against its neighbours, September runs about 9°F cooler than August and about 15°F warmer than October.

20°40°60°80°151015202530
Avg high (°F)Avg low (°F)
17553
27553
37453
47452
57452
67351
77351
87251
97250
107150
117149
127049
137048
147048
156948
166947
176847
186846
196746
206746
216745
226645
236644
246544
256543
266443
276443
286442
296342
306241

How September really feels in Jamestown

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.

Jamestown weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan18° / 0.74.75.28.80.0
Feb22° / 0.74.84.9100.0
Mar34° / 18°1.25.84.111.60.0
Apr51° / 31°1.87.82.713.32.6
May65° / 44°3.210.80.414.85.7
Jun74° / 55°4.511.6015.66.5
Jul79° / 59°3.69.7015.37.0
Aug78° / 56°2.98.50147.3
Sep69° / 47°2.57.4012.46.9
Oct54° / 35°2.16.91.310.63.5
Nov37° / 20°1.04.94.19.20.1
Dec23° / 0.95.15.48.40.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 43%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16535
26436
36337
46238
56139
65941
75941
85842
95743
105644
115545
125545
135446
145347
155347
165347
175347
185347
195446
205446
215446
225644
235644
245644
255644
265644
275743
285644
295644
305644

Chance of precipitation in September

Any precipitation

Jamestown gets around 2.5 in of rain over 7.4 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 25% and peaks near 26% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
125
224
324
424
524
624
724
824
924
1024
1124
1224
1325
1425
1525
1625
1726
1826
1926
2026
2125
2225
2325
2425
2525
2625
2724
2824
2924
3024

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 79% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
15526145
25725135
35924125
46124114
56323104
6662293
7682183
8682183
9712072
10731962
11731962
12751852
13771751
14791641
15801541
16811441
17831331
18841231
19851131
20871021
2188921
2290820
2391720
2493610
2593610
2694510
2795410
2895410
2996310
3097300

Wind in September

Winds average 10 mph in September.

Across September, daily wind ranges from about 9 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
19light breeze
29light breeze
39light breeze
49light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light breeze
129light breeze
139light breeze
1410light breeze
1510light breeze
1610light breeze
1710light breeze
1810light breeze
1910light breeze
2010light breeze
2110light breeze
2210light breeze
2310light breeze
2410light breeze
2510light breeze
2610light breeze
2710light breeze
2810light breeze
2910light breeze
3010light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 12 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over September. Sunrise moves from 5:59 AM to 6:38 AM, and sunset from 7:10 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:597:10
213.16:007:08
313.16:027:06
413.06:037:04
513.06:047:02
612.96:067:00
712.86:076:58
812.86:086:56
912.76:106:54
1012.76:116:52
1112.66:136:50
1212.66:146:47
1312.56:156:45
1412.46:176:43
1512.46:186:41
1612.36:196:39
1712.36:216:37
1812.26:226:35
1912.26:236:33
2012.16:256:31
2112.06:266:29
2212.06:276:27
2311.96:296:24
2411.96:306:22
2511.86:316:20
2611.86:336:18
2711.76:346:16
2811.66:366:14
2911.66:376:12
3011.56:386:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.2 kWh/m².

For context, solar energy here swings from a low near 1.39 kWh/m² to a high of 6.46 kWh/m² in July across the year — September's 4.2 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
15.0Bright
24.9Bright
34.9Bright
44.8Bright
54.7Bright
64.7Bright
74.6Bright
84.6Bright
94.5Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.2Bright
154.2Bright
164.1Bright
174.1Bright
184.0Bright
194.0Moderate
204.0Moderate
213.9Moderate
223.9Moderate
233.8Moderate
243.8Moderate
253.8Moderate
263.7Moderate
273.7Moderate
283.6Moderate
293.6Moderate
303.5Moderate
Planning a trip in September

Hazard calendar for Jamestown

In seasonPeak

In September, Jamestown sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Jamestown's rainy season runs May–October, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Jamestown?

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

6.9
Sightseeing
3rd-best month of the year
3.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Jamestown for sightseeing.

What to pack for Jamestown in September

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

In September, Jamestown sees daytime highs around 69°F and nights near 47°F. Little to plan around — just the basics. About 7 days see rain.

UV index in Jamestown in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Jamestown peaks around June 19 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 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 highHighModerateLowJun 19UV 8Dec 20UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr4Moderate
May6High
Jun9Very high
Jul8Very high
Aug7High
Sep5High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Jamestown in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Jamestown is worst in August — around 15 µg/m³ PM2.5 (moderate), about 2.9× the cleanest month (October, 5 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1215 µg/m³Oct 205 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar12Moderate
Apr11Good
May10Good
Jun9Good
Jul14Moderate
Aug15Moderate
Sep10Good
Oct5Good
Nov7Good
Dec8Good
Location & terrain

Where is Jamestown?

Jamestown sits at 46.9°N, 98.7°W, 1,407 ft above sea level, in United States. The nearest listed city is West Fargo, 85 mi away.

Topography around Jamestown

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

Within 2 miles, the terrain around Jamestown has only modest variations in elevation — a maximum elevation change of 141 ft around an average of 1,457 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 259 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,135 ft.

The land around Jamestown is covered by grassland (39%) and artificial surfaces (28%) within 2 miles, cropland (66%) and grassland (27%) within 10 miles, and cropland (64%) and grassland (30%) within 50 miles.

2 miles
141 ft
10 miles
259 ft
50 miles
1,135 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: West Fargo 85 mi · Fargo 91 mi · Moorhead 91 mi · Bismarck 98 mi · Aberdeen 101 mi · Mandan 103 mi · Grand Forks 105 mi · Minot 151 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 Jamestown (46.9105°, -98.7084°, elevation 1,407 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. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).