Fort St. John weather in September

In September, Fort St. John sees average daytime highs of 15°C and overnight lows near 5°C, with 43 mm of precipitation across 8.1 wet days and about 12.5 hours of daylight. It is the 5th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 17°C in the first days to 13°C by the end. The sky is clear or mostly clear about 27% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 42 min at the start of September to 11 h 18 min by month's end. Set against the rest of the year, September is Fort St. John's 2nd-clearest and 2nd-windiest month. For the whole year in context, see Fort St. John's year-round climate.

Daytime high
15°
5th warmest
Overnight low
9th coldest
Precipitation
43 mm
8.1 wet days
Daylight
12 h 30 min
6:44 AM – 7:12 PM
Cloud cover
61%
2nd clearest
Wind
10 km/h
2nd windiest
Solar energy
3.38 kWh/m²
Travel score
4.8
out of 10

Fort St. John is city in British Columbia, Canada.

Air quality
Good
PM2.5 9 µg/m³ · 2018
Density
946/km²
people per km²
Founded
1975

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 17°C in the first days to 13°C by the end.

A typical September day in Fort St. John reaches about 15°C in the afternoon and slips back to 5°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 9°C and 22°C. Set against its neighbours, September runs about 5°C cooler than August and about 8°C warmer than October.

10°20°151015202530
Avg high (°C)Avg low (°C)
1187
2187
3187
4176
5176
6176
7176
8176
9166
10165
11165
12165
13165
14165
15155
16154
17154
18154
19154
20154
21144
22144
23143
24143
25143
26133
27133
28133
29132
30122

How September really feels in Fort St. John

Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 4 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
4
wind chill below the day's low

The story in September is cold — wind chill drags the overnight "feels like" below the raw low.

Fort St. John weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-9° / -17°257.17.67.30.0
Feb-6° / -14°164.55.39.10.0
Mar-0° / -10°236.67.111.40.0
Apr / -2°255.73.413.81.8
May16° / 408.21.1165.1
Jun20° / 7510.9017.36.0
Jul22° / 10°8011.3016.86.4
Aug21° / 478.6014.96.6
Sep15° / 438.10.512.54.8
Oct / -1°337.33.710.11.2
Nov-3° / -10°317.47.37.90.0
Dec-8° / -15°235.66.46.70.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14654
24753
34654
44654
54555
64555
74456
84555
94456
104456
114357
124357
134357
144258
154258
164258
174258
184258
194258
204258
214357
224456
234456
244456
254456
264456
274456
284456
294456
304456

Chance of precipitation in September

Any precipitationSnow

Fort St. John gets around 43 mm of rain and snow over 8.1 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 27% and peaks near 31% on the wettest days, and about 1 day brings snow. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)Snow chance (%)
1300
2300
3311
4311
5311
6311
7311
8311
9301
10301
11291
12291
13281
14271
15262
16252
17252
18242
19242
20232
21232
22232
23233
24233
25233
26233
27233
28234
29234
30234

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 10 km/h in September.

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

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 42 min at the start of September to 11 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 144 minutes over September. Sunrise moves from 6:13 AM to 7:13 AM, and sunset from 7:53 PM to 6:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.76:137:53
213.66:157:50
313.56:177:47
413.46:197:45
513.36:217:42
613.36:237:39
713.26:267:37
813.16:287:34
913.06:307:31
1012.96:327:28
1112.96:347:26
1212.86:367:23
1312.76:387:20
1412.66:407:17
1512.56:427:14
1612.56:447:12
1712.46:467:09
1812.36:487:06
1912.26:507:03
2012.16:527:00
2112.16:546:58
2212.06:566:55
2311.96:586:52
2411.87:006:49
2511.77:026:47
2611.77:046:44
2711.67:066:41
2811.57:086:38
2911.47:116:36
3011.37:136:33

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.38 kWh/m².

For context, solar energy here swings from a low near 0.54 kWh/m² to a high of 6.23 kWh/m² in June across the year — September's 3.38 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.1Bright
24.0Bright
34.0Moderate
43.9Moderate
53.9Moderate
63.8Moderate
73.8Moderate
83.7Moderate
93.7Moderate
103.6Moderate
113.6Moderate
123.5Moderate
133.5Moderate
143.5Moderate
153.4Moderate
163.4Moderate
173.3Moderate
183.3Moderate
193.2Moderate
203.2Moderate
213.1Moderate
223.1Moderate
233.0Moderate
243.0Moderate
252.9Moderate
262.9Moderate
272.8Moderate
282.8Moderate
292.7Moderate
302.7Moderate
Planning a trip in September

Is September a good time to visit Fort St. John?

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

4.8
Sightseeing
5th-best month of the year
0.6
Beach & pool
5th-best month of the year

September is a reasonable time to visit Fort St. John for sightseeing.

What to pack for Fort St. John in September

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

In September, Fort St. John sees daytime highs around 15°C and nights near 5°C. Worth packing: a warm layer and rain gear. About 8 days see rain.

a warm layerrain gear

UV index in Fort St. John in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Fort St. John peaks around July 13 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 19 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 5 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJul 13UV 7Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Moderate
Apr3Moderate
May4Moderate
Jun6High
Jul7High
Aug4Moderate
Sep3Moderate
Oct1Low
Nov1Low
Dec0Low

Air quality in Fort St. John 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 Fort St. John is worst in May — around 22 µg/m³ PM2.5 (moderate), about 5.3× the cleanest month (March, 4 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Fort St. John's WHO annual average of 9 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 1720 µg/m³Mar 154 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb5Good
Mar4Good
Apr6Good
May22Moderate
Jun8Good
Jul12Good
Aug9Good
Sep6Good
Oct7Good
Nov12Good
Dec11Good
Location & terrain

Where is Fort St. John?

Fort St. John sits at 56.2°N, 120.9°W, 696 m above sea level, in Canada. The nearest listed city is Grande Prairie, 176 km away.

Prince GeorgeJasperTerraceStony PlainSpruce GroveSt. AlbertWîhkwêntôwin

Topography around Fort St. John

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

Within 3 km, the terrain around Fort St. John has only modest variations in elevation — a maximum elevation change of 126 m around an average of 685 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 466 m; within 80 km, large variations in elevation — a maximum elevation change of 963 m.

The land around Fort St. John is covered by artificial surfaces (32%), trees (26%) and grassland (25%) within 3 km, trees (50%) and grassland (24%) within 16 km, and trees (67%) and grassland (20%) within 80 km.

3 km
126 m
16 km
466 m
80 km
963 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Grande Prairie 176 km · Prince George 286 km · Jasper 415 km · Terrace 526 km · Stony Plain 532 km · Spruce Grove 536 km · St. Albert 545 km · Wîhkwêntôwin 557 km

Canada travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 83% of US
price level, 2025
GDP per capita
$55,698
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
2
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 53%none 35%Muslim 5%Hindu 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 Fort St. John (56.2499°, -120.8529°, elevation 696 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).