Los Álamos weather in September

In September, Los Álamos sees average daytime highs of 12°C and overnight lows near 8°C, with 90 mm of rain across 10.1 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 12°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 h 12 min at the start of September to 12 h 18 min by month's end. Set against the rest of the year, September is Los Álamos's 8th-clearest and 8th-windiest month. For the whole year in context, see Los Álamos's year-round climate.

Daytime high: 12°; 9th warmest
Overnight low: 8°; 3rd coldest
Rainfall: 90 mm; 10.1 wet days
Daylight: 11 h 48 min; 7:55 AM – 7:41 PM
Cloud cover: 56%; 8th clearest
Wind: 16 km/h; 8th windiest
Solar energy: 4.29 kWh/m²
Travel score: 3.3; out of 10

← August Los Álamos 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 12°C through the month.

A typical September day in Los Álamos reaches about 12°C in the afternoon and slips back to 8°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 10°C and 14°C. Set against its neighbours, September runs about 1°C warmer than August and about 1°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)	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	13	13	13	13	13	13	13	13	13	13	13
Avg low (°C)	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8

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

Los Álamos 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	18° / 12°	15	2.9	14.3	7.5
Feb	18° / 12°	19	2.7	13.5	7.5
Mar	17° / 12°	33	5.1	12.3	6.6
Apr	15° / 10°	77	7.6	11.1	4.9
May	13° / 9°	172	12.4	10	3.5
Jun	12° / 8°	254	16.4	9.5	2.5
Jul	11° / 7°	208	15.6	9.7	2.4
Aug	11° / 7°	174	14.4	10.6	2.6
Sep	12° / 8°	90	10.1	11.7	3.3
Oct	13° / 9°	74	9.3	13	4.0
Nov	15° / 10°	42	6	14	5.1
Dec	17° / 11°	36	4.6	14.6	6.4

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 15% of September, with mostly cloudy or overcast conditions the remaining 52%.

	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 (%)	39	40	42	43	45	45	47	47	47	47	48	48	49	49	49	49	50	50	50	51	51	51	51	51	51	51	51	52	52	52
Cloudier (%)	61	60	58	57	55	55	53	53	53	53	52	52	51	51	51	51	50	50	50	49	49	49	49	49	49	49	49	48	48	48

	Clearer (%)	Cloudier (%)
1	39	61
2	40	60
3	42	58
4	43	57
5	45	55
6	45	55
7	47	53
8	47	53
9	47	53
10	47	53
11	48	52
12	48	52
13	49	51
14	49	51
15	49	51
16	49	51
17	50	50
18	50	50
19	50	50
20	51	49
21	51	49
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	52	48
29	52	48
30	52	48

Chance of precipitation in September

Any precipitation

Los Álamos gets around 90 mm of rain over 10.1 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 43% on the wettest days. The odds ease toward the end of the month.

	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 (%)	43	42	42	41	40	39	38	38	37	37	37	36	35	35	34	33	32	32	31	31	30	30	30	30	30	30	30	29	29	29

	Rain chance (%)
1	43
2	42
3	42
4	41
5	40
6	39
7	38
8	38
9	37
10	37
11	37
12	36
13	35
14	35
15	34
16	33
17	32
18	32
19	31
20	31
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

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 16 km/h in September.

Across September, daily wind ranges from about 16 km/h on the calmest days to 17 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)	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	16	16	16	16	16	16	16	16	16	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	17	light breeze
2	17	light breeze
3	17	light breeze
4	17	light breeze
5	17	light breeze
6	17	light breeze
7	17	light breeze
8	17	light breeze
9	17	light breeze
10	17	light breeze
11	17	light breeze
12	17	light breeze
13	17	light breeze
14	17	light breeze
15	17	light breeze
16	16	light breeze
17	16	light breeze
18	16	light breeze
19	16	light breeze
20	16	light breeze
21	16	light breeze
22	16	light breeze
23	16	light breeze
24	16	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 h 12 min at the start of September to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over September. Sunrise moves from 8:19 AM to 7:33 AM, and sunset from 7:28 PM to 7:53 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)	11.2	11.2	11.2	11.3	11.3	11.4	11.4	11.4	11.5	11.5	11.6	11.6	11.6	11.7	11.7	11.8	11.8	11.8	11.9	11.9	12.0	12.0	12.1	12.1	12.1	12.2	12.2	12.3	12.3	12.3
Sunrise (AM)	8:19	8:18	8:16	8:14	8:13	8:11	8:10	8:08	8:07	8:05	8:03	8:02	8:00	7:59	7:57	7:55	7:54	7:52	7:50	7:49	7:47	7:46	7:44	7:42	7:41	7:39	7:38	7:36	7:34	7:33
Sunset (PM)	7:28	7:29	7:30	7:31	7:32	7:32	7:33	7:34	7:35	7:36	7:37	7:38	7:38	7:39	7:40	7:41	7:42	7:43	7:44	7:45	7:45	7:46	7:47	7:48	7:49	7:50	7:51	7:52	7:52	7:53

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.2	8:19	7:28
2	11.2	8:18	7:29
3	11.2	8:16	7:30
4	11.3	8:14	7:31
5	11.3	8:13	7:32
6	11.4	8:11	7:32
7	11.4	8:10	7:33
8	11.4	8:08	7:34
9	11.5	8:07	7:35
10	11.5	8:05	7:36
11	11.6	8:03	7:37
12	11.6	8:02	7:38
13	11.6	8:00	7:38
14	11.7	7:59	7:39
15	11.7	7:57	7:40
16	11.8	7:55	7:41
17	11.8	7:54	7:42
18	11.8	7:52	7:43
19	11.9	7:50	7:44
20	11.9	7:49	7:45
21	12.0	7:47	7:45
22	12.0	7:46	7:46
23	12.1	7:44	7:47
24	12.1	7:42	7:48
25	12.1	7:41	7:49
26	12.2	7:39	7:50
27	12.2	7:38	7:51
28	12.3	7:36	7:52
29	12.3	7:34	7:52
30	12.3	7:33	7:53

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.29 kWh/m².

For context, solar energy here swings from a low near 1.68 kWh/m² to a high of 8.3 kWh/m² in January across the year — September's 4.29 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	3.7	3.7	3.8	3.9	3.9	4.0	4.0	4.1	4.2	4.2	4.3	4.3	4.4	4.4	4.5	4.5	4.6	4.6	4.7	4.7	4.8	4.8	4.9	4.9	5.0	5.0
Level	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	Bright	Bright

	Solar energy (kWh/m²)	Level
1	3.4	Moderate
2	3.5	Moderate
3	3.5	Moderate
4	3.6	Moderate
5	3.7	Moderate
6	3.7	Moderate
7	3.8	Moderate
8	3.9	Moderate
9	3.9	Moderate
10	4.0	Moderate
11	4.0	Bright
12	4.1	Bright
13	4.2	Bright
14	4.2	Bright
15	4.3	Bright
16	4.3	Bright
17	4.4	Bright
18	4.4	Bright
19	4.5	Bright
20	4.5	Bright
21	4.6	Bright
22	4.6	Bright
23	4.7	Bright
24	4.7	Bright
25	4.8	Bright
26	4.8	Bright
27	4.9	Bright
28	4.9	Bright
29	5.0	Bright
30	5.0	Bright

Planning a trip in September

Hazard calendar for Los Álamos

In seasonPeak

None of Los Álamos's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Los Álamos's rainy season runs May–August, when most of the year's rain falls.

Rainy season

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Is September a good time to visit Los Álamos?

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

3.3

Sightseeing

9th-best month of the year

0.0

Beach & pool

7th-best month of the year

September is a weaker month for outdoor sightseeing in Los Álamos.

What to pack for Los Álamos in September

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

In September, Los Álamos sees daytime highs around 12°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Los Álamos 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 15 km away) is warmest in January at about 15°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)	15	15	15	14	13	13	12	12	12	12	13	14
Comfort	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing

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

UV index in Los Álamos 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 Los Álamos peaks around December 23 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 16 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)	12	11	8	5	2	2	2	3	5	8	10	12
Level	Extreme	Extreme	Very high	Moderate	Moderate	Low	Moderate	Moderate	Moderate	Very high	Very high	Extreme

	UV index (midday)	Level
Jan	12	Extreme
Feb	11	Extreme
Mar	8	Very high
Apr	5	Moderate
May	2	Moderate
Jun	2	Low
Jul	2	Moderate
Aug	3	Moderate
Sep	5	Moderate
Oct	8	Very high
Nov	10	Very high
Dec	12	Extreme

Location & terrain

Where is Los Álamos?

Los Álamos sits at 37.6°S, 73.5°W, 178 m above sea level, in Chile. The nearest listed city is Lebu, 17 km away.

Topography around Los Álamos

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

Within 3 km, the terrain around Los Álamos has only modest variations in elevation — a maximum elevation change of 160 m around an average of 166 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 821 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,511 m.

The land around Los Álamos is covered by trees (82%) within 3 km, trees (85%) within 16 km, and trees (49%) and water (39%) within 80 km.

3 km

160 m

trees 82%

16 km

821 m

trees 85%

80 km

1,511 m

trees 49%

treesgrasslandcroplandartificial surfaceswater

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

September weather nearby: Lebu 17 km · Curanilahue 20 km · Cañete 20 km · Arauco 44 km · Lota 66 km · Angol 68 km · Nacimiento 71 km · Coronel 72 km

Chile travel facts

Travel advisory: Level 2; Exercise Increased Caution
Power plugs: Type C / F / L; 220 V · 50 Hz
Prices: ≈ 48% of US; price level, 2025
GDP per capita: $17,995; 2025
Happiness: 6.3 / 10; World Happiness, 2025
Safe drinking water: 98%; of population, 2024
Homicide rate: 6.3; per 100k, 2023
Road deaths: 14.9; per 100k/yr, 2019
Income group: High; World Bank
English: Moderate; EF EPI 517
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 Los Álamos (-37.628°, -73.4601°, elevation 178 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	12	8
2	12	8
3	12	8
4	12	8
5	12	8
6	12	8
7	12	8
8	12	8
9	12	8
10	12	8
11	12	8
12	12	8
13	12	8
14	12	8
15	12	8
16	12	8
17	12	8
18	12	8
19	12	8
20	13	8
21	13	8
22	13	8
23	13	8
24	13	8
25	13	8
26	13	8
27	13	8
28	13	8
29	13	8
30	13	8

	Clearer (%)	Cloudier (%)
1	39	61
2	40	60
3	42	58
4	43	57
5	45	55
6	45	55
7	47	53
8	47	53
9	47	53
10	47	53
11	48	52
12	48	52
13	49	51
14	49	51
15	49	51
16	49	51
17	50	50
18	50	50
19	50	50
20	51	49
21	51	49
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	52	48
29	52	48
30	52	48

	Rain chance (%)
1	43
2	42
3	42
4	41
5	40
6	39
7	38
8	38
9	37
10	37
11	37
12	36
13	35
14	35
15	34
16	33
17	32
18	32
19	31
20	31
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

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

	Clearer (%)	Cloudier (%)
1	39	61
2	40	60
3	42	58
4	43	57
5	45	55
6	45	55
7	47	53
8	47	53
9	47	53
10	47	53
11	48	52
12	48	52
13	49	51
14	49	51
15	49	51
16	49	51
17	50	50
18	50	50
19	50	50
20	51	49
21	51	49
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	52	48
29	52	48
30	52	48

	Rain chance (%)
1	43
2	42
3	42
4	41
5	40
6	39
7	38
8	38
9	37
10	37
11	37
12	36
13	35
14	35
15	34
16	33
17	32
18	32
19	31
20	31
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

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

	Clearer (%)	Cloudier (%)
1	39	61
2	40	60
3	42	58
4	43	57
5	45	55
6	45	55
7	47	53
8	47	53
9	47	53
10	47	53
11	48	52
12	48	52
13	49	51
14	49	51
15	49	51
16	49	51
17	50	50
18	50	50
19	50	50
20	51	49
21	51	49
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	52	48
29	52	48
30	52	48

	Rain chance (%)
1	43
2	42
3	42
4	41
5	40
6	39
7	38
8	38
9	37
10	37
11	37
12	36
13	35
14	35
15	34
16	33
17	32
18	32
19	31
20	31
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

	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