Northampton weather in September

In September, Northampton sees average daytime highs of 18°C and overnight lows near 10°C, with 54 mm of rain across 9.4 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 16°C by the end. The sky is clear or mostly clear about 13% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 24 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Northampton's 5th-clearest and 9th-windiest month. For the whole year in context, see Northampton's year-round climate.

Daytime high
18°
4th warmest
Overnight low
10°
9th coldest
Rainfall
54 mm
9.4 wet days
Daylight
12 h 24 min
5:46 AM – 6:10 PM
Cloud cover
72%
5th clearest
Wind
15 km/h
9th windiest
Solar energy
2.93 kWh/m²
Travel score
5.6
out of 10

Northampton is town and civil parish in Northamptonshire, England, UK.

Air quality
Moderate
PM2.5 11.6 µg/m³ · 2019
Density
3,045/km²
people per km²
Founded
1189

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 19°C in the first days to 16°C by the end.

A typical September day in Northampton reaches about 18°C in the afternoon and slips back to 10°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 22°C. Set against its neighbours, September runs about 3°C cooler than August and about 4°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11911
21911
31911
41911
51911
61911
71911
81911
91911
101911
111811
121811
131811
141810
151810
161810
171810
181810
191810
201710
211710
221710
231710
241710
251710
261710
271710
28169
29169
30169

How September really feels in Northampton

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

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
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.

Northampton weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 5311.61.180.8
Feb / 429.81.59.51.0
Mar10° / 4510.3111.52.1
Apr13° / 5211.30.213.63.3
May16° / 5710.8015.44.7
Jun19° / 11°6010.5016.45.7
Jul21° / 13°6211.50166.1
Aug21° / 13°6110.9014.56.1
Sep18° / 10°549.4012.45.6
Oct14° / 6211.2010.33.8
Nov10° / 5911.20.38.52.0
Dec / 57110.97.60.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 72%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13169
23070
33070
43070
53070
63070
72971
82971
92971
102872
112872
122872
132872
142872
152872
162773
172773
182773
192674
202674
212674
222773
232773
242773
252674
262674
272674
282674
292674
302674

Chance of precipitation in September

Any precipitation

Northampton gets around 54 mm of rain over 9.4 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 32% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
131
230
330
430
530
630
730
830
930
1030
1130
1230
1330
1431
1531
1631
1731
1831
1931
2032
2132
2232
2333
2433
2533
2634
2735
2835
2936
3036

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 82% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
175223
275223
376213
476213
577212
678202
778202
878202
979192
1079192
1180182
1280182
1381172
1482162
1582162
1683161
1784151
1884151
1984151
2084151
2185150
2285150
2385150
2486140
2586140
2687130
2787130
2888120
2988120
3089110

Wind in September

Winds average 15 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2816light breeze
2916light breeze
3016light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 24 min at the start of September to 11 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 120 minutes over September. Sunrise moves from 5:20 AM to 6:10 AM, and sunset from 6:46 PM to 5:36 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:206:46
213.45:226:44
313.35:246:41
413.25:256:39
513.25:276:37
613.15:296:34
713.05:316:32
813.05:326:29
912.95:346:27
1012.85:366:25
1112.75:376:22
1212.75:396:20
1312.65:416:17
1412.55:426:15
1512.55:446:12
1612.45:466:10
1712.35:486:07
1812.35:496:05
1912.25:516:02
2012.15:536:00
2112.15:545:58
2212.05:565:55
2311.95:585:53
2411.86:005:50
2511.86:015:48
2611.76:035:45
2711.66:055:43
2811.66:075:40
2911.56:085:38
3011.46:105:36

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.93 kWh/m².

For context, solar energy here swings from a low near 0.61 kWh/m² to a high of 5.05 kWh/m² in June across the year — September's 2.93 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.4Moderate
43.4Moderate
53.4Moderate
63.3Moderate
73.3Moderate
83.3Moderate
93.2Moderate
103.2Moderate
113.1Moderate
123.1Moderate
133.0Moderate
143.0Moderate
152.9Moderate
162.9Moderate
172.8Moderate
182.8Moderate
192.8Moderate
202.7Moderate
212.7Moderate
222.6Moderate
232.6Moderate
242.5Moderate
252.5Moderate
262.5Moderate
272.4Moderate
282.4Moderate
292.3Moderate
302.3Moderate
Planning a trip in September

Is September a good time to visit Northampton?

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

5.6
Sightseeing
4th-best month of the year
1.8
Beach & pool
4th-best month of the year

September is a reasonable time to visit Northampton for sightseeing.

What to pack for Northampton in September

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

In September, Northampton sees daytime highs around 18°C and nights near 10°C. Worth packing: rain gear. About 9 days see rain.

rain gear

UV index in Northampton in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Northampton peaks around August 11 at about 6 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowAug 11UV 6Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr3Moderate
May5High
Jun6High
Jul6High
Aug6High
Sep4Moderate
Oct2Moderate
Nov1Low
Dec1Low

Air quality in Northampton 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 Northampton is worst in April — around 15 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (November, 9 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Northampton's WHO annual average of 11.6 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1115 µg/m³Nov 179 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb11Good
Mar15Moderate
Apr15Moderate
May13Moderate
Jun12Good
Jul11Good
Aug11Good
Sep11Good
Oct10Good
Nov9Good
Dec9Good
Location & terrain

Where is Northampton?

Northampton sits at 52.3°N, 0.9°W, 97 m above sea level, in United Kingdom. The nearest listed city is Wellingborough, 14 km away.

Topography around Northampton

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Northampton.

Within 3 km, the terrain around Northampton has only modest variations in elevation — a maximum elevation change of 85 m around an average of 84 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 158 m; within 80 km, significant variations in elevation — a maximum elevation change of 389 m.

The land around Northampton is covered by artificial surfaces (49%) and trees (32%) within 3 km, cropland (46%) and grassland (29%) within 16 km, and cropland (47%) and grassland (31%) within 80 km.

3 km
85 m
16 km
158 m
80 km
389 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Wellingborough 14 km · Daventry 19 km · Rushden 20 km · Kettering 20 km · Newport Pagnell 21 km · Milton Keynes 25 km · Market Harborough 25 km · Rugby 29 km

United Kingdom travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type D / G / M
230 V · 50 Hz
Prices
≈ 89% of US
price level, 2025
GDP per capita
$57,602
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2021
Road deaths
3.2
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 60%none 26%Muslim 4%other 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 Northampton (52.25°, -0.8833°, elevation 97 m), 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).