St Austell weather in September

In September, St Austell sees average daytime highs of 17°C and overnight lows near 13°C, with 58 mm of rain across 10.2 wet days and about 12.4 hours of daylight. It is the 3rd-warmest and 12th-wettest month of the year here.

Highs ease over the month, from about 18°C in the first days to 16°C by the end. The sky is clear or mostly clear about 16% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 18 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is St Austell's 3rd-clearest and 9th-windiest month. For the whole year in context, see St Austell's year-round climate.

Daytime high
17°
3rd warmest
Overnight low
13°
10th coldest
Rainfall
58 mm
10.2 wet days
Daylight
12 h 24 min
6:02 AM – 6:25 PM
Cloud cover
68%
3rd clearest
Wind
18 km/h
9th windiest
Solar energy
3.23 kWh/m²
Travel score
5.4
out of 10

St Austell is town in Cornwall, England, UK.

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 18°C in the first days to 16°C by the end.

A typical September day in St Austell reaches about 17°C in the afternoon and slips back to 13°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 19°C. Set against its neighbours, September runs about 2°C cooler than August and about 3°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11813
21813
31813
41813
51813
61813
71813
81813
91813
101813
111813
121713
131713
141713
151713
161713
171713
181712
191712
201712
211712
221712
231712
241712
251612
261612
271612
281612
291612
301612

St Austell weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan / 8614.48.31.6
Feb / 6811.79.71.6
Mar10° / 6411.811.52.1
Apr12° / 6612.413.52.9
May14° / 6311.415.24.0
Jun17° / 12°6311.416.15.1
Jul19° / 14°6310.615.75.9
Aug19° / 14°6711.114.35.8
Sep17° / 13°5810.212.45.4
Oct14° / 11°9013.510.53.8
Nov12° / 9114.48.82.6
Dec10° / 91147.91.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 16% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 19% of September, with mostly cloudy or overcast conditions the remaining 66%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13565
23565
33565
43466
53565
63565
73466
83466
93466
103466
113466
123565
133565
143565
153664
163664
173565
183664
193664
203565
213565
223565
233466
243367
253367
263367
273367
283268
293268
303268

Chance of precipitation in September

Any precipitation

St Austell gets around 58 mm of rain over 10.2 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 34% and peaks near 43% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
129
229
329
429
529
629
729
830
930
1030
1130
1230
1331
1431
1531
1632
1732
1833
1934
2035
2136
2237
2338
2439
2540
2641
2742
2842
2943
3043

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 62% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
150437
251427
351427
452417
553407
654397
755387
855378
956368
1058357
1159347
1260337
1362326
1462326
1563316
1664315
1764315
1865314
1965314
2066313
2166313
2267312
2367312
2467312
2568311
2669301
2770291
2870291
2971281
3072271

Wind in September

Winds average 18 km/h in September.

Across September, daily wind ranges from about 17 km/h on the calmest days to 19 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
117light breeze
218light breeze
318light breeze
418light breeze
518light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1419light breeze
1519light breeze
1619light breeze
1719light breeze
1819light breeze
1919light breeze
2019light breeze
2119light breeze
2219light breeze
2319light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2919light breeze
3019light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 18 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 108 minutes over September. Sunrise moves from 5:39 AM to 6:24 AM, and sunset from 6:59 PM to 5:52 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:396:59
213.35:406:57
313.25:426:54
413.15:436:52
513.15:456:50
613.05:476:48
713.05:486:45
812.95:506:43
912.85:516:41
1012.85:536:38
1112.75:546:36
1212.65:566:34
1312.65:586:32
1412.55:596:29
1512.46:016:27
1612.46:026:25
1712.36:046:22
1812.26:056:20
1912.26:076:18
2012.16:096:15
2112.06:106:13
2212.06:126:11
2311.96:136:08
2411.96:156:06
2511.86:166:04
2611.76:186:01
2711.76:205:59
2811.66:215:57
2911.56:235:55
3011.56:245:52

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.23 kWh/m².

For context, solar energy here swings from a low near 0.73 kWh/m² to a high of 5.47 kWh/m² in June across the year — September's 3.23 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.8Moderate
43.7Moderate
53.7Moderate
63.6Moderate
73.6Moderate
83.6Moderate
93.5Moderate
103.5Moderate
113.5Moderate
123.4Moderate
133.4Moderate
143.3Moderate
153.3Moderate
163.3Moderate
173.2Moderate
183.2Moderate
193.1Moderate
203.1Moderate
213.0Moderate
223.0Moderate
232.9Moderate
242.9Moderate
252.8Moderate
262.8Moderate
272.7Moderate
282.6Moderate
292.6Moderate
302.6Moderate
Planning a trip in September

Is September a good time to visit St Austell?

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

5.4
Sightseeing
3rd-best month of the year
1.4
Beach & pool
3rd-best month of the year

September is a reasonable time to visit St Austell for sightseeing.

What to pack for St Austell in September

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

In September, St Austell sees daytime highs around 17°C and nights near 13°C. Worth packing: rain gear. About 10 days see rain.

rain gear

Sea temperature near St Austell in September

The nearest coast averages about 16°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 25 km away) is warmest in August at about 17°C and coldest in March near 9°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

10°15°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan10Bracing
Feb10Bracing
Mar9Bracing
Apr10Bracing
May12Bracing
Jun14Bracing
Jul16Cool
Aug17Cool
Sep16Cool
Oct15Bracing
Nov13Bracing
Dec11Bracing

UV index in St Austell 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 St Austell peaks around August 13 at about 7 (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 13UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr5Moderate
May6High
Jun6High
Jul6High
Aug7High
Sep5Moderate
Oct3Moderate
Nov1Low
Dec1Low
Location & terrain

Where is St Austell?

St Austell sits at 50.3°N, 4.8°W, 73 m above sea level, in United Kingdom. The nearest listed city is Bodmin, 15 km away.

Topography around St Austell

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

Within 3 km, the terrain around St Austell has significant variations in elevation — a maximum elevation change of 266 m around an average of 94 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 362 m; within 80 km, large variations in elevation — a maximum elevation change of 613 m.

The land around St Austell is covered by trees (36%) and grassland (34%) within 3 km, grassland (40%), water (26%) and trees (20%) within 16 km, and water (59%) and grassland (28%) within 80 km.

3 km
266 m
16 km
362 m
80 km
613 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Bodmin 15 km · Truro 22 km · Newquay 23 km · Falmouth 30 km · Redruth 34 km · Saltash 40 km · Camborne 40 km · Plymouth 45 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 St Austell (50.3425°, -4.7744°, elevation 73 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).