Antioch weather in September

In September, Antioch sees average daytime highs of 82°F and overnight lows near 58°F, with 0.0 in of rain across 0.3 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 84°F in the first days to 81°F by the end. The sky is clear or mostly clear about 86% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Antioch's 3rd-clearest and 6th-windiest month. For the whole year in context, see Antioch's year-round climate.

Daytime high: 82°; 3rd warmest
Overnight low: 58°; 10th coldest
Rainfall: 0.0 in; 0.3 wet days
Daylight: 12 h 12 min; 5:54 AM – 6:09 PM
Cloud cover: 14%; 3rd clearest
Wind: 6 mph; 6th windiest
Solar energy: 6.01 kWh/m²
Travel score: 8.3; out of 10

Antioch is city in California, United States.

Density: 1,417/km²; people per km²
Founded: 1872

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

← August Antioch year-round climate October →Best places to visit in September

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 84°F in the first days to 81°F by the end.

A typical September day in Antioch reaches about 82°F in the afternoon and slips back to 58°F overnight — a 25°F spread between the day's warmth and the night's chill. On most days the high lands between 75°F and 91°F. Set against its neighbours, September runs about 2°F cooler than August and about 6°F warmer than October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°F)	84	84	84	84	84	83	83	83	83	83	83	83	82	82	82	82	82	82	82	82	82	82	82	81	81	81	81	81	80	80
Avg low (°F)	59	59	59	59	59	59	58	58	58	58	58	58	58	58	58	58	57	57	57	57	57	57	57	57	57	57	56	56	56	56

	Avg high (°F)	Avg low (°F)
1	84	59
2	84	59
3	84	59
4	84	59
5	84	59
6	83	59
7	83	58
8	83	58
9	83	58
10	83	58
11	83	58
12	83	58
13	82	58
14	82	58
15	82	58
16	82	58
17	82	57
18	82	57
19	82	57
20	82	57
21	82	57
22	82	57
23	82	57
24	81	57
25	81	57
26	81	57
27	81	56
28	81	56
29	80	56
30	80	56

Antioch weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 11th-wettest month here — the current month is highlighted below.

Month	High / Low (°F)	Rainfall (inches)	Wet days	Daylight (hours)	Travel score
Jan	57° / 43°	3.7	9	9.7	4.2
Feb	61° / 45°	3.5	8.8	10.5	5.2
Mar	66° / 48°	2.7	8.3	11.7	6.4
Apr	70° / 50°	1.2	4.7	13	7.6
May	76° / 54°	0.6	3	14	8.5
Jun	82° / 57°	0.1	0.7	14.6	8.3
Jul	84° / 59°	0.0	0.2	14.4	7.7
Aug	84° / 59°	0.1	0.2	13.5	7.7
Sep	82° / 58°	0.0	0.3	12.3	8.3
Oct	76° / 54°	0.9	2.8	11	8.6
Nov	65° / 47°	1.8	5.4	9.9	6.6
Dec	57° / 43°	3.4	8.4	9.4	4.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 86% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 7% of September, with mostly cloudy or overcast conditions the remaining 7%. Skies tend to cloud over as the month goes on.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	97	97	97	97	97	97	97	96	96	96	96	96	95	95	94	94	93	93	93	92	92	92	90	90	90	89	89	89	88	88
Cloudier (%)	3	3	3	3	3	3	3	4	4	4	4	4	5	5	6	6	7	7	7	8	8	8	10	10	10	11	11	11	12	12

	Clearer (%)	Cloudier (%)
1	97	3
2	97	3
3	97	3
4	97	3
5	97	3
6	97	3
7	97	3
8	96	4
9	96	4
10	96	4
11	96	4
12	96	4
13	95	5
14	95	5
15	94	6
16	94	6
17	93	7
18	93	7
19	93	7
20	92	8
21	92	8
22	92	8
23	90	10
24	90	10
25	90	10
26	89	11
27	89	11
28	89	11
29	88	12
30	88	12

Chance of precipitation in September

Any precipitation

Antioch gets around 0.0 in of rain over 0.3 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 1% and peaks near 4% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	0	0	0	0	0	0	0	0	0	1	1	1	1	1	1	1	1	1	2	2	2	2	2	2	3	3	3	3	4	4

	Rain chance (%)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	2
20	2
21	2
22	2
23	2
24	2
25	3
26	3
27	3
28	3
29	4
30	4

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.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	55	57	58	59	60	61	62	63	63	65	65	65	65	65	65	65	64	64	65	65	65	66	66	67	68	69	70	71	72	74
Comfortable (%)	41	39	38	37	36	35	34	33	33	32	32	32	32	33	33	33	34	34	34	34	34	33	33	32	31	30	29	28	27	25
Humid (%)	4	4	4	4	4	4	4	4	4	3	3	3	3	2	2	2	2	2	1	1	1	1	1	1	1	1	1	1	1	1

	Dry (%)	Comfortable (%)	Humid (%)
1	55	41	4
2	57	39	4
3	58	38	4
4	59	37	4
5	60	36	4
6	61	35	4
7	62	34	4
8	63	33	4
9	63	33	4
10	65	32	3
11	65	32	3
12	65	32	3
13	65	32	3
14	65	33	2
15	65	33	2
16	65	33	2
17	64	34	2
18	64	34	2
19	65	34	1
20	65	34	1
21	65	34	1
22	66	33	1
23	66	33	1
24	67	32	1
25	68	31	1
26	69	30	1
27	70	29	1
28	71	28	1
29	72	27	1
30	74	25	1

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (mph)	7	7	7	7	7	7	7	7	7	7	7	7	7	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (mph)	Feels
1	7	calm
2	7	calm
3	7	calm
4	7	calm
5	7	calm
6	7	calm
7	7	calm
8	7	calm
9	7	calm
10	7	calm
11	7	calm
12	7	calm
13	7	calm
14	6	calm
15	6	calm
16	6	calm
17	6	calm
18	6	calm
19	6	calm
20	6	calm
21	6	calm
22	6	calm
23	6	calm
24	6	calm
25	6	calm
26	6	calm
27	6	calm
28	6	calm
29	6	calm
30	6	calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over September. Sunrise moves from 5:41 AM to 6:07 AM, and sunset from 6:33 PM to 5:46 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	12.9	12.8	12.8	12.7	12.7	12.7	12.6	12.6	12.5	12.5	12.5	12.4	12.4	12.3	12.3	12.2	12.2	12.2	12.1	12.1	12.0	12.0	11.9	11.9	11.9	11.8	11.8	11.7	11.7	11.7
Sunrise (AM)	5:41	5:42	5:43	5:44	5:45	5:45	5:46	5:47	5:48	5:49	5:50	5:51	5:52	5:53	5:53	5:54	5:55	5:56	5:57	5:58	5:59	6:00	6:01	6:01	6:02	6:03	6:04	6:05	6:06	6:07
Sunset (PM)	6:33	6:31	6:30	6:28	6:27	6:25	6:23	6:22	6:20	6:19	6:17	6:15	6:14	6:12	6:10	6:09	6:07	6:06	6:04	6:02	6:01	5:59	5:57	5:56	5:54	5:53	5:51	5:49	5:48	5:46

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.9	5:41	6:33
2	12.8	5:42	6:31
3	12.8	5:43	6:30
4	12.7	5:44	6:28
5	12.7	5:45	6:27
6	12.7	5:45	6:25
7	12.6	5:46	6:23
8	12.6	5:47	6:22
9	12.5	5:48	6:20
10	12.5	5:49	6:19
11	12.5	5:50	6:17
12	12.4	5:51	6:15
13	12.4	5:52	6:14
14	12.3	5:53	6:12
15	12.3	5:53	6:10
16	12.2	5:54	6:09
17	12.2	5:55	6:07
18	12.2	5:56	6:06
19	12.1	5:57	6:04
20	12.1	5:58	6:02
21	12.0	5:59	6:01
22	12.0	6:00	5:59
23	11.9	6:01	5:57
24	11.9	6:01	5:56
25	11.9	6:02	5:54
26	11.8	6:03	5:53
27	11.8	6:04	5:51
28	11.7	6:05	5:49
29	11.7	6:06	5:48
30	11.7	6:07	5:46

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.01 kWh/m².

For context, solar energy here swings from a low near 2.16 kWh/m² to a high of 8.13 kWh/m² in June across the year — September's 6.01 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	6.7	6.7	6.7	6.6	6.6	6.5	6.5	6.4	6.4	6.3	6.3	6.2	6.1	6.1	6.0	6.0	5.9	5.9	5.8	5.8	5.7	5.7	5.6	5.5	5.5	5.4	5.4	5.3	5.3	5.2
Level	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	6.7	Intense
2	6.7	Intense
3	6.7	Intense
4	6.6	Intense
5	6.6	Intense
6	6.5	Intense
7	6.5	Intense
8	6.4	Intense
9	6.4	Intense
10	6.3	Intense
11	6.3	Intense
12	6.2	Intense
13	6.1	Intense
14	6.1	Intense
15	6.0	Intense
16	6.0	Bright
17	5.9	Bright
18	5.9	Bright
19	5.8	Bright
20	5.8	Bright
21	5.7	Bright
22	5.7	Bright
23	5.6	Bright
24	5.5	Bright
25	5.5	Bright
26	5.4	Bright
27	5.4	Bright
28	5.3	Bright
29	5.3	Bright
30	5.2	Bright

Planning a trip in September

Is September a good time to visit Antioch?

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

8.3

Sightseeing

3rd-best month of the year

9.1

Beach & pool

3rd-best month of the year

September is one of the better times to visit Antioch for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Antioch in September

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

In September, Antioch sees daytime highs around 82°F and nights near 58°F. Pack light clothes and sun protection.

light clothessun protection

UV index in Antioch 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 Antioch peaks around June 23 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	2	4	4	6	8	10	10	10	6	5	2	2
Level	Moderate	Moderate	Moderate	High	Very high	Very high	Very high	Very high	High	High	Moderate	Low

	UV index (midday)	Level
Jan	2	Moderate
Feb	4	Moderate
Mar	4	Moderate
Apr	6	High
May	8	Very high
Jun	10	Very high
Jul	10	Very high
Aug	10	Very high
Sep	6	High
Oct	5	High
Nov	2	Moderate
Dec	2	Low

Air quality in Antioch 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 Antioch is worst in August — around 27 µg/m³ PM2.5 (moderate), about 3.6× the cleanest month (June, 8 µg/m³).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	15	14	15	12	9	8	11	27	23	17	19	14
Level	Moderate	Moderate	Moderate	Good	Good	Good	Good	Moderate	Moderate	Moderate	Moderate	Moderate

	PM2.5 (µg/m³)	Level
Jan	15	Moderate
Feb	14	Moderate
Mar	15	Moderate
Apr	12	Good
May	9	Good
Jun	8	Good
Jul	11	Good
Aug	27	Moderate
Sep	23	Moderate
Oct	17	Moderate
Nov	19	Moderate
Dec	14	Moderate

Location & terrain

Where is Antioch?

Antioch sits at 38.0°N, 121.8°W, 43 ft above sea level, in United States. The nearest listed city is Pittsburg, 4.3 mi away.

Topography around Antioch

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

Within 2 miles, the terrain around Antioch has only modest variations in elevation — a maximum elevation change of 253 ft around an average of 59 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,501 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,452 ft.

The land around Antioch is covered by artificial surfaces (54%) within 2 miles, grassland (43%) within 10 miles, and grassland (33%) and trees (23%) within 50 miles.

2 miles

253 ft

artificial surfaces 54%

10 miles

3,501 ft

grassland 43%

50 miles

4,452 ft

grassland 33%

treesgrasslandcroplandartificial surfacesbare terrainwaterwetland

← August Antioch year-round climate October →Best places to visit in September

September weather nearby: Pittsburg 4.3 mi · Oakley 5.0 mi · Brentwood 8.1 mi · Bay Point 8.7 mi · Concord 12 mi · Pleasant Hill 14 mi · Walnut Creek 16 mi · Danville 17 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

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 Antioch (38.0049°, -121.8058°, elevation 43 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).

	Avg high (°F)	Avg low (°F)
1	84	59
2	84	59
3	84	59
4	84	59
5	84	59
6	83	59
7	83	58
8	83	58
9	83	58
10	83	58
11	83	58
12	83	58
13	82	58
14	82	58
15	82	58
16	82	58
17	82	57
18	82	57
19	82	57
20	82	57
21	82	57
22	82	57
23	82	57
24	81	57
25	81	57
26	81	57
27	81	56
28	81	56
29	80	56
30	80	56

	Clearer (%)	Cloudier (%)
1	97	3
2	97	3
3	97	3
4	97	3
5	97	3
6	97	3
7	97	3
8	96	4
9	96	4
10	96	4
11	96	4
12	96	4
13	95	5
14	95	5
15	94	6
16	94	6
17	93	7
18	93	7
19	93	7
20	92	8
21	92	8
22	92	8
23	90	10
24	90	10
25	90	10
26	89	11
27	89	11
28	89	11
29	88	12
30	88	12

	Rain chance (%)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	2
20	2
21	2
22	2
23	2
24	2
25	3
26	3
27	3
28	3
29	4
30	4

	Dry (%)	Comfortable (%)	Humid (%)
1	55	41	4
2	57	39	4
3	58	38	4
4	59	37	4
5	60	36	4
6	61	35	4
7	62	34	4
8	63	33	4
9	63	33	4
10	65	32	3
11	65	32	3
12	65	32	3
13	65	32	3
14	65	33	2
15	65	33	2
16	65	33	2
17	64	34	2
18	64	34	2
19	65	34	1
20	65	34	1
21	65	34	1
22	66	33	1
23	66	33	1
24	67	32	1
25	68	31	1
26	69	30	1
27	70	29	1
28	71	28	1
29	72	27	1
30	74	25	1

	Avg high (°F)	Avg low (°F)
1	84	59
2	84	59
3	84	59
4	84	59
5	84	59
6	83	59
7	83	58
8	83	58
9	83	58
10	83	58
11	83	58
12	83	58
13	82	58
14	82	58
15	82	58
16	82	58
17	82	57
18	82	57
19	82	57
20	82	57
21	82	57
22	82	57
23	82	57
24	81	57
25	81	57
26	81	57
27	81	56
28	81	56
29	80	56
30	80	56

	Clearer (%)	Cloudier (%)
1	97	3
2	97	3
3	97	3
4	97	3
5	97	3
6	97	3
7	97	3
8	96	4
9	96	4
10	96	4
11	96	4
12	96	4
13	95	5
14	95	5
15	94	6
16	94	6
17	93	7
18	93	7
19	93	7
20	92	8
21	92	8
22	92	8
23	90	10
24	90	10
25	90	10
26	89	11
27	89	11
28	89	11
29	88	12
30	88	12

	Rain chance (%)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	2
20	2
21	2
22	2
23	2
24	2
25	3
26	3
27	3
28	3
29	4
30	4

	Dry (%)	Comfortable (%)	Humid (%)
1	55	41	4
2	57	39	4
3	58	38	4
4	59	37	4
5	60	36	4
6	61	35	4
7	62	34	4
8	63	33	4
9	63	33	4
10	65	32	3
11	65	32	3
12	65	32	3
13	65	32	3
14	65	33	2
15	65	33	2
16	65	33	2
17	64	34	2
18	64	34	2
19	65	34	1
20	65	34	1
21	65	34	1
22	66	33	1
23	66	33	1
24	67	32	1
25	68	31	1
26	69	30	1
27	70	29	1
28	71	28	1
29	72	27	1
30	74	25	1

	Avg high (°F)	Avg low (°F)
1	84	59
2	84	59
3	84	59
4	84	59
5	84	59
6	83	59
7	83	58
8	83	58
9	83	58
10	83	58
11	83	58
12	83	58
13	82	58
14	82	58
15	82	58
16	82	58
17	82	57
18	82	57
19	82	57
20	82	57
21	82	57
22	82	57
23	82	57
24	81	57
25	81	57
26	81	57
27	81	56
28	81	56
29	80	56
30	80	56

	Clearer (%)	Cloudier (%)
1	97	3
2	97	3
3	97	3
4	97	3
5	97	3
6	97	3
7	97	3
8	96	4
9	96	4
10	96	4
11	96	4
12	96	4
13	95	5
14	95	5
15	94	6
16	94	6
17	93	7
18	93	7
19	93	7
20	92	8
21	92	8
22	92	8
23	90	10
24	90	10
25	90	10
26	89	11
27	89	11
28	89	11
29	88	12
30	88	12

	Rain chance (%)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	2
20	2
21	2
22	2
23	2
24	2
25	3
26	3
27	3
28	3
29	4
30	4

	Dry (%)	Comfortable (%)	Humid (%)
1	55	41	4
2	57	39	4
3	58	38	4
4	59	37	4
5	60	36	4
6	61	35	4
7	62	34	4
8	63	33	4
9	63	33	4
10	65	32	3
11	65	32	3
12	65	32	3
13	65	32	3
14	65	33	2
15	65	33	2
16	65	33	2
17	64	34	2
18	64	34	2
19	65	34	1
20	65	34	1
21	65	34	1
22	66	33	1
23	66	33	1
24	67	32	1
25	68	31	1
26	69	30	1
27	70	29	1
28	71	28	1
29	72	27	1
30	74	25	1