Santa Rosa weather in September

In September, Santa Rosa sees average daytime highs of 25°C and overnight lows near 14°C, with 152 mm of rain across 10.4 wet days and about 11.8 hours of daylight. It is the 8th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 42% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 24 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is Santa Rosa's 5th-clearest and 1st-windiest month. For the whole year in context, see Santa Rosa's year-round climate.

Daytime high
25°
8th warmest
Overnight low
14°
5th coldest
Rainfall
152 mm
10.4 wet days
Daylight
11 h 48 min
7:37 AM – 7:27 PM
Cloud cover
52%
5th clearest
Wind
12 km/h
1st windiest
Solar energy
4.59 kWh/m²
Travel score
7.0
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 25°C through the month.

A typical September day in Santa Rosa reaches about 25°C in the afternoon and slips back to 14°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 31°C. Set against its neighbours, September runs about 2°C warmer than August and about 2°C cooler than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12413
22413
32413
42413
52413
62414
72414
82414
92414
102414
112414
122414
132414
142414
152414
162414
172414
182414
192414
202514
212514
222514
232514
242514
252515
262515
272515
282515
292515
302515

How September really feels in Santa Rosa

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

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Santa Rosa weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 21°14314.513.63.9
Feb31° / 21°13614134.2
Mar30° / 19°12711.812.25.0
Apr27° / 17°1559.711.46.6
May23° / 13°1529.410.66.9
Jun21° / 12°1439.710.36.5
Jul20° / 11°1379.410.46.6
Aug23° / 12°948.5117.3
Sep25° / 14°15210.411.87.0
Oct27° / 16°21512.912.76.1
Nov29° / 18°1561113.45.5
Dec31° / 20°16013.113.74.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 42% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 11% of September, with mostly cloudy or overcast conditions the remaining 47%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
25842
35842
45743
55743
65545
75446
85446
95446
105347
115347
125347
135347
145347
155248
165248
175248
185248
195248
205248
215248
225149
235149
245149
255050
265050
274951
284852
294753
304654

Chance of precipitation in September

Any precipitation

Santa Rosa gets around 152 mm of rain over 10.4 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 35% and peaks near 39% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
130
231
331
431
531
632
732
832
933
1033
1133
1233
1333
1434
1534
1634
1735
1835
1935
2036
2136
2237
2337
2437
2538
2638
2738
2839
2939
3039

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 38% of days. Sticky, muggy-or-worse air turns up on roughly 9% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
14131244
24031244
34031245
44030255
54030255
64030256
74029256
84029256
94028257
104028257
114027268
123927268
133926269
143926269
1539262610
1639252610
1739252610
1839242710
1938242711
2038242711
2138242711
2237242811
2336242812
2436242912
2535242913
2634242913
2733242914
2832243014
2932243015
3031243015

Wind in September

Winds average 12 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 12 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
112calm
212calm
312calm
412calm
512calm
612calm
712calm
812calm
912calm
1012calm
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812calm
2912calm
3012calm

Sunrise & sunset in September

DaylightNight

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

Days grow by about 48 minutes over September. Sunrise moves from 7:55 AM to 7:20 AM, and sunset from 7:20 PM to 7:34 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.47:557:20
211.47:547:21
311.57:537:21
411.57:527:22
511.57:507:22
611.67:497:23
711.67:487:23
811.67:477:24
911.67:467:24
1011.77:447:24
1111.77:437:25
1211.77:427:25
1311.87:417:26
1411.87:407:26
1511.87:387:27
1611.87:377:27
1711.97:367:28
1811.97:357:28
1911.97:337:29
2012.07:327:29
2112.07:317:30
2212.07:307:30
2312.07:297:31
2412.17:277:31
2512.17:267:32
2612.17:257:32
2712.17:247:33
2812.27:237:33
2912.27:217:34
3012.27:207:34

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.59 kWh/m².

For context, solar energy here swings from a low near 2.61 kWh/m² to a high of 6.63 kWh/m² in December across the year — September's 4.59 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.3Bright
44.4Bright
54.4Bright
64.4Bright
74.4Bright
84.4Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.6Bright
164.6Bright
174.6Bright
184.6Bright
194.7Bright
204.7Bright
214.7Bright
224.7Bright
234.8Bright
244.8Bright
254.8Bright
264.8Bright
274.8Bright
284.8Bright
294.9Bright
304.9Bright
Planning a trip in September

Is September a good time to visit Santa Rosa?

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

7.0
Sightseeing
2nd-best month of the year
6.1
Beach & pool
6th-best month of the year

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

What to pack for Santa Rosa in September

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

In September, Santa Rosa sees daytime highs around 25°C and nights near 14°C. Worth packing: light clothes, rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

UV index in Santa Rosa in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Santa Rosa peaks around January 20 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 4 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateVery highExtremeJan 20UV 14Jun 21UV 4
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar11Extreme
Apr8Very high
May5High
Jun4Moderate
Jul4Moderate
Aug5High
Sep8Very high
Oct7Very high
Nov11Extreme
Dec12Extreme

Air quality in Santa Rosa 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 Santa Rosa is worst in September — around 17 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (March, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1516 µg/m³Mar 137 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb7Good
Mar7Good
Apr8Good
May7Good
Jun7Good
Jul8Good
Aug13Moderate
Sep17Moderate
Oct11Good
Nov8Good
Dec7Good
Location & terrain

Where is Santa Rosa?

Santa Rosa sits at 27.9°S, 54.5°W, 284 m above sea level, in Brazil. The nearest listed city is Santo Cristo, 19 km away.

Topography around Santa Rosa

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

Within 3 km, the terrain around Santa Rosa has only modest variations in elevation — a maximum elevation change of 137 m around an average of 273 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 268 m; within 80 km, significant variations in elevation — a maximum elevation change of 487 m.

The land around Santa Rosa is covered by trees (37%) and artificial surfaces (32%) within 3 km, cropland (61%) and trees (29%) within 16 km, and cropland (47%) and trees (39%) within 80 km.

3 km
137 m
16 km
268 m
80 km
487 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Santo Cristo 19 km · Giruá 22 km · Três de Maio 26 km · Horizontina 32 km · Santo Ângelo 52 km · El Soberbio 70 km · Três Passos 71 km · Oberá 76 km

Brazil travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / N
127 / 220 V · 60 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$10,713
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
19.3
per 100k, 2023
Road deaths
16
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 482
Religion
Roman Catholic 57%Evangelical 27%none 9%other 4%

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 Santa Rosa (-27.8708°, -54.4814°, elevation 284 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).