Blenheim weather in September

In September, Blenheim sees average daytime highs of 13°C and overnight lows near 7°C, with 73 mm of rain across 10.3 wet days and about 11.7 hours of daylight. It is the 9th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 13°C through the month. The sky is clear or mostly clear about 33% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 hours at the start of September to 12 h 24 min by month's end. Set against the rest of the year, September is Blenheim's 8th-clearest and 5th-windiest month. For the whole year in context, see Blenheim's year-round climate.

Daytime high: 13°; 9th warmest
Overnight low: 7°; 4th coldest
Rainfall: 73 mm; 10.3 wet days
Daylight: 11 h 42 min; 7:27 AM – 7:10 PM
Cloud cover: 56%; 8th clearest
Wind: 15 km/h; 5th windiest
Solar energy: 4.06 kWh/m²
Travel score: 3.8; out of 10

Blenheim is town in New Zealand.

Air quality: Good; PM10 18.5 µg/m³ · 2012
Density: 287/km²; people per km²
Founded: 1850

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

← August Blenheim 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

Day-to-day highs hold fairly steady near 13°C through the month.

A typical September day in Blenheim reaches about 13°C in the afternoon and slips back to 7°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 10°C and 16°C. Set against its neighbours, September runs about 2°C warmer than August and about 2°C cooler 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 (°C)	13	13	13	13	13	13	13	13	13	13	13	13	13	13	13	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14
Avg low (°C)	6	6	6	6	6	6	6	6	6	6	6	6	6	6	7	7	7	7	7	7	7	7	7	7	7	7	7	7	7	7

	Avg high (°C)	Avg low (°C)
1	13	6
2	13	6
3	13	6
4	13	6
5	13	6
6	13	6
7	13	6
8	13	6
9	13	6
10	13	6
11	13	6
12	13	6
13	13	6
14	13	6
15	13	7
16	14	7
17	14	7
18	14	7
19	14	7
20	14	7
21	14	7
22	14	7
23	14	7
24	14	7
25	14	7
26	14	7
27	14	7
28	14	7
29	14	7
30	14	7

Blenheim weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 5th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	20° / 13°	60	8.1	14.7	6.6
Feb	20° / 13°	53	6.3	13.7	6.9
Mar	19° / 11°	53	7.1	12.3	6.6
Apr	16° / 9°	67	8.2	10.9	5.5
May	14° / 7°	63	8.4	9.7	4.4
Jun	12° / 5°	81	9.4	9.1	3.1
Jul	11° / 5°	76	9.7	9.3	2.7
Aug	12° / 5°	74	10.8	10.3	3.1
Sep	13° / 7°	73	10.3	11.7	3.8
Oct	15° / 8°	83	11.1	13.1	4.6
Nov	17° / 10°	73	9.9	14.3	5.4
Dec	19° / 12°	73	10.4	14.9	6.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% 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 48%.

	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 (%)	53	52	52	52	51	50	49	50	50	50	50	51	52	52	53	53	53	53	53	53	53	53	53	52	52	52	51	51	50	50
Cloudier (%)	47	48	48	48	49	50	51	50	50	50	50	49	48	48	47	47	47	47	47	47	47	47	47	48	48	48	49	49	50	50

	Clearer (%)	Cloudier (%)
1	53	47
2	52	48
3	52	48
4	52	48
5	51	49
6	50	50
7	49	51
8	50	50
9	50	50
10	50	50
11	50	50
12	51	49
13	52	48
14	52	48
15	53	47
16	53	47
17	53	47
18	53	47
19	53	47
20	53	47
21	53	47
22	53	47
23	53	47
24	52	48
25	52	48
26	52	48
27	51	49
28	51	49
29	50	50
30	50	50

Chance of precipitation in September

Any precipitation

Blenheim gets around 73 mm of rain over 10.3 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 34% and peaks near 36% 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 (%)	33	33	33	32	32	32	33	33	33	33	33	33	34	34	34	34	34	34	34	35	35	35	35	35	35	35	35	35	36	36

	Rain chance (%)
1	33
2	33
3	33
4	32
5	32
6	32
7	33
8	33
9	33
10	33
11	33
12	33
13	34
14	34
15	34
16	34
17	34
18	34
19	34
20	35
21	35
22	35
23	35
24	35
25	35
26	35
27	35
28	35
29	36
30	36

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.

	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 (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

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.

	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 (km/h)	14	14	14	14	14	14	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	16	16	16	16	16	16
Feels	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze

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

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 hours at the start of September to 12 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 84 minutes over September. Sunrise moves from 7:53 AM to 7:02 AM, and sunset from 6:55 PM to 7:25 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)	11.0	11.1	11.1	11.2	11.2	11.3	11.3	11.3	11.4	11.4	11.5	11.5	11.6	11.6	11.7	11.7	11.8	11.8	11.9	11.9	12.0	12.0	12.1	12.1	12.2	12.2	12.2	12.3	12.3	12.4
Sunrise (AM)	7:53	7:51	7:50	7:48	7:46	7:45	7:43	7:41	7:39	7:37	7:36	7:34	7:32	7:30	7:29	7:27	7:25	7:23	7:21	7:20	7:18	7:16	7:14	7:12	7:11	7:09	7:07	7:05	7:03	7:02
Sunset (PM)	6:55	6:56	6:57	6:58	6:59	7:00	7:01	7:02	7:03	7:04	7:05	7:06	7:07	7:08	7:09	7:10	7:11	7:12	7:13	7:15	7:16	7:17	7:18	7:19	7:20	7:21	7:22	7:23	7:24	7:25

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.0	7:53	6:55
2	11.1	7:51	6:56
3	11.1	7:50	6:57
4	11.2	7:48	6:58
5	11.2	7:46	6:59
6	11.3	7:45	7:00
7	11.3	7:43	7:01
8	11.3	7:41	7:02
9	11.4	7:39	7:03
10	11.4	7:37	7:04
11	11.5	7:36	7:05
12	11.5	7:34	7:06
13	11.6	7:32	7:07
14	11.6	7:30	7:08
15	11.7	7:29	7:09
16	11.7	7:27	7:10
17	11.8	7:25	7:11
18	11.8	7:23	7:12
19	11.9	7:21	7:13
20	11.9	7:20	7:15
21	12.0	7:18	7:16
22	12.0	7:16	7:17
23	12.1	7:14	7:18
24	12.1	7:12	7:19
25	12.2	7:11	7:20
26	12.2	7:09	7:21
27	12.2	7:07	7:22
28	12.3	7:05	7:23
29	12.3	7:03	7:24
30	12.4	7:02	7:25

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.06 kWh/m².

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 7.31 kWh/m² in January across the year — September's 4.06 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)	3.4	3.5	3.5	3.6	3.6	3.6	3.7	3.8	3.8	3.9	3.9	4.0	4.0	4.0	4.1	4.1	4.2	4.2	4.3	4.3	4.3	4.4	4.4	4.5	4.5	4.5	4.6	4.6	4.6	4.7
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	3.4	Moderate
2	3.5	Moderate
3	3.5	Moderate
4	3.6	Moderate
5	3.6	Moderate
6	3.6	Moderate
7	3.7	Moderate
8	3.8	Moderate
9	3.8	Moderate
10	3.9	Moderate
11	3.9	Moderate
12	4.0	Moderate
13	4.0	Bright
14	4.0	Bright
15	4.1	Bright
16	4.1	Bright
17	4.2	Bright
18	4.2	Bright
19	4.3	Bright
20	4.3	Bright
21	4.3	Bright
22	4.4	Bright
23	4.4	Bright
24	4.5	Bright
25	4.5	Bright
26	4.5	Bright
27	4.6	Bright
28	4.6	Bright
29	4.6	Bright
30	4.7	Bright

Planning a trip in September

Is September a good time to visit Blenheim?

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

3.8

Sightseeing

9th-best month of the year

0.0

Beach & pool

9th-best month of the year

September is a weaker month for outdoor sightseeing in Blenheim.

What to pack for Blenheim in September

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

In September, Blenheim sees daytime highs around 13°C and nights near 7°C. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Blenheim in September

The nearest coast averages about 12°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 21 km away) is warmest in February at about 17°C and coldest in August near 12°C.

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sea temperature (°C)	16	17	16	15	14	13	12	12	12	13	14	15
Comfort	Cool	Cool	Cool	Cool	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing

	Sea temperature (°C)	Comfort
Jan	16	Cool
Feb	17	Cool
Mar	16	Cool
Apr	15	Cool
May	14	Bracing
Jun	13	Bracing
Jul	12	Bracing
Aug	12	Bracing
Sep	12	Bracing
Oct	13	Bracing
Nov	14	Bracing
Dec	15	Bracing

UV index in Blenheim 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 Blenheim peaks around January 11 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 16 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	11	10	6	4	2	1	2	3	4	6	9	11
Level	Extreme	Extreme	High	Moderate	Low	Low	Low	Moderate	Moderate	High	Very high	Extreme

	UV index (midday)	Level
Jan	11	Extreme
Feb	10	Extreme
Mar	6	High
Apr	4	Moderate
May	2	Low
Jun	1	Low
Jul	2	Low
Aug	3	Moderate
Sep	4	Moderate
Oct	6	High
Nov	9	Very high
Dec	11	Extreme

Location & terrain

Where is Blenheim?

Blenheim sits at 41.5°S, 174.0°E, 9 m above sea level, in New Zealand. The nearest listed city is Picton, 25 km away.

Topography around Blenheim

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

Within 3 km, the terrain around Blenheim has only modest variations in elevation — a maximum elevation change of 79 m around an average of 9 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 899 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,829 m.

The land around Blenheim is covered by grassland (47%) and artificial surfaces (32%) within 3 km, grassland (53%) and trees (24%) within 16 km, and water (47%), trees (28%) and grassland (21%) within 80 km.

3 km

79 m

grassland 47%

16 km

899 m

grassland 53%

80 km

2,829 m

water 47%

treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland

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

September weather nearby: Picton 25 km · Nelson 62 km · Stoke 64 km · Richmond 67 km · Karori 71 km · Wellington 73 km · Porirua 86 km · Lower Hutt 87 km

New Zealand travel facts

Travel advisory: Level 1; Exercise Normal Precautions
Power plugs: Type I; 230 V · 50 Hz
Prices: ≈ 86% of US; price level, 2025
GDP per capita: $49,591; 2025
Happiness: 7.0 / 10; World Happiness, 2025
Safe drinking water: 100%; of population, 2024
Homicide rate: 1.5; per 100k, 2022
Road deaths: 9.6; 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 Blenheim (-41.516°, 173.9528°, elevation 9 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).

	Avg high (°C)	Avg low (°C)
1	13	6
2	13	6
3	13	6
4	13	6
5	13	6
6	13	6
7	13	6
8	13	6
9	13	6
10	13	6
11	13	6
12	13	6
13	13	6
14	13	6
15	13	7
16	14	7
17	14	7
18	14	7
19	14	7
20	14	7
21	14	7
22	14	7
23	14	7
24	14	7
25	14	7
26	14	7
27	14	7
28	14	7
29	14	7
30	14	7

	Clearer (%)	Cloudier (%)
1	53	47
2	52	48
3	52	48
4	52	48
5	51	49
6	50	50
7	49	51
8	50	50
9	50	50
10	50	50
11	50	50
12	51	49
13	52	48
14	52	48
15	53	47
16	53	47
17	53	47
18	53	47
19	53	47
20	53	47
21	53	47
22	53	47
23	53	47
24	52	48
25	52	48
26	52	48
27	51	49
28	51	49
29	50	50
30	50	50

	Rain chance (%)
1	33
2	33
3	33
4	32
5	32
6	32
7	33
8	33
9	33
10	33
11	33
12	33
13	34
14	34
15	34
16	34
17	34
18	34
19	34
20	35
21	35
22	35
23	35
24	35
25	35
26	35
27	35
28	35
29	36
30	36

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

	Avg high (°C)	Avg low (°C)
1	13	6
2	13	6
3	13	6
4	13	6
5	13	6
6	13	6
7	13	6
8	13	6
9	13	6
10	13	6
11	13	6
12	13	6
13	13	6
14	13	6
15	13	7
16	14	7
17	14	7
18	14	7
19	14	7
20	14	7
21	14	7
22	14	7
23	14	7
24	14	7
25	14	7
26	14	7
27	14	7
28	14	7
29	14	7
30	14	7

	Clearer (%)	Cloudier (%)
1	53	47
2	52	48
3	52	48
4	52	48
5	51	49
6	50	50
7	49	51
8	50	50
9	50	50
10	50	50
11	50	50
12	51	49
13	52	48
14	52	48
15	53	47
16	53	47
17	53	47
18	53	47
19	53	47
20	53	47
21	53	47
22	53	47
23	53	47
24	52	48
25	52	48
26	52	48
27	51	49
28	51	49
29	50	50
30	50	50

	Rain chance (%)
1	33
2	33
3	33
4	32
5	32
6	32
7	33
8	33
9	33
10	33
11	33
12	33
13	34
14	34
15	34
16	34
17	34
18	34
19	34
20	35
21	35
22	35
23	35
24	35
25	35
26	35
27	35
28	35
29	36
30	36

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

	Avg high (°C)	Avg low (°C)
1	13	6
2	13	6
3	13	6
4	13	6
5	13	6
6	13	6
7	13	6
8	13	6
9	13	6
10	13	6
11	13	6
12	13	6
13	13	6
14	13	6
15	13	7
16	14	7
17	14	7
18	14	7
19	14	7
20	14	7
21	14	7
22	14	7
23	14	7
24	14	7
25	14	7
26	14	7
27	14	7
28	14	7
29	14	7
30	14	7

	Clearer (%)	Cloudier (%)
1	53	47
2	52	48
3	52	48
4	52	48
5	51	49
6	50	50
7	49	51
8	50	50
9	50	50
10	50	50
11	50	50
12	51	49
13	52	48
14	52	48
15	53	47
16	53	47
17	53	47
18	53	47
19	53	47
20	53	47
21	53	47
22	53	47
23	53	47
24	52	48
25	52	48
26	52	48
27	51	49
28	51	49
29	50	50
30	50	50

	Rain chance (%)
1	33
2	33
3	33
4	32
5	32
6	32
7	33
8	33
9	33
10	33
11	33
12	33
13	34
14	34
15	34
16	34
17	34
18	34
19	34
20	35
21	35
22	35
23	35
24	35
25	35
26	35
27	35
28	35
29	36
30	36

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100