Petrópolis weather in September
In September, Petrópolis sees average daytime highs of 26°C and overnight lows near 17°C, with 88 mm of rain across 10.7 wet days and about 11.9 hours of daylight. It is the 8th-warmest and 8th-wettest month of the year here.
Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 33% of the time in September, and the air most often feels humid.
Daylight stretches from about 11 h 30 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is Petrópolis's 5th-clearest and 1st-windiest month. For the whole year in context, see Petrópolis's year-round climate.
- Daytime high
- 26°
- 8th warmest
- Overnight low
- 17°
- 5th coldest
- Rainfall
- 88 mm
- 10.7 wet days
- Daylight
- 11 h 54 min
- 6:51 AM – 6:43 PM
- Cloud cover
- 59%
- 5th clearest
- Wind
- 6 km/h
- 1st windiest
- Solar energy
- 4.52 kWh/m²
- Travel score
- 6.6
- out of 10
Temperature in September
Day-to-day highs hold fairly steady near 26°C through the month.
A typical September day in Petrópolis reaches about 26°C in the afternoon and slips back to 17°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 30°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) | 25 | 25 | 25 | 25 | 25 | 25 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 25 | 25 | 26 | 26 | 26 | 26 | 26 | 26 | 26 |
| Avg low (°C) | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 25 | 16 |
| 2 | 25 | 16 |
| 3 | 25 | 16 |
| 4 | 25 | 16 |
| 5 | 25 | 16 |
| 6 | 25 | 16 |
| 7 | 26 | 16 |
| 8 | 26 | 16 |
| 9 | 26 | 16 |
| 10 | 26 | 16 |
| 11 | 26 | 16 |
| 12 | 26 | 16 |
| 13 | 26 | 17 |
| 14 | 26 | 17 |
| 15 | 26 | 17 |
| 16 | 26 | 17 |
| 17 | 26 | 17 |
| 18 | 26 | 17 |
| 19 | 26 | 17 |
| 20 | 26 | 17 |
| 21 | 26 | 17 |
| 22 | 25 | 17 |
| 23 | 25 | 17 |
| 24 | 26 | 17 |
| 25 | 26 | 17 |
| 26 | 26 | 17 |
| 27 | 26 | 17 |
| 28 | 26 | 17 |
| 29 | 26 | 17 |
| 30 | 26 | 17 |
How September really feels in Petrópolis
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.
September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Petrópolis weather by month
How September compares with the rest of the year at a glance. September is the 8th-warmest and 8th-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 29° / 21° | 315 | 22.8 | 13.2 | 3.7 |
| Feb | 30° / 21° | 231 | 18.5 | 12.8 | 3.9 |
| Mar | 29° / 21° | 244 | 22.1 | 12.2 | 4.2 |
| Apr | 27° / 19° | 105 | 14.1 | 11.5 | 5.8 |
| May | 25° / 16° | 70 | 11 | 10.9 | 6.8 |
| Jun | 24° / 15° | 41 | 7 | 10.6 | 7.6 |
| Jul | 24° / 15° | 40 | 6.6 | 10.8 | 7.8 |
| Aug | 25° / 15° | 42 | 7.2 | 11.2 | 7.6 |
| Sep | 26° / 17° | 88 | 10.7 | 11.9 | 6.6 |
| Oct | 26° / 18° | 137 | 15.1 | 12.5 | 5.7 |
| Nov | 27° / 19° | 252 | 20 | 13.1 | 4.8 |
| Dec | 28° / 21° | 296 | 23.3 | 13.4 | 4.1 |
Cloud cover in September
The sky is clear or mostly clear about 33% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 54%. 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 (%) | 61 | 61 | 60 | 59 | 59 | 58 | 57 | 55 | 53 | 52 | 51 | 49 | 48 | 46 | 45 | 44 | 43 | 41 | 40 | 39 | 37 | 36 | 36 | 35 | 34 | 34 | 33 | 33 | 33 | 33 |
| Cloudier (%) | 39 | 39 | 40 | 41 | 41 | 42 | 43 | 45 | 47 | 48 | 49 | 51 | 52 | 54 | 55 | 56 | 57 | 59 | 60 | 61 | 63 | 64 | 64 | 65 | 66 | 66 | 67 | 67 | 67 | 67 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 61 | 39 |
| 2 | 61 | 39 |
| 3 | 60 | 40 |
| 4 | 59 | 41 |
| 5 | 59 | 41 |
| 6 | 58 | 42 |
| 7 | 57 | 43 |
| 8 | 55 | 45 |
| 9 | 53 | 47 |
| 10 | 52 | 48 |
| 11 | 51 | 49 |
| 12 | 49 | 51 |
| 13 | 48 | 52 |
| 14 | 46 | 54 |
| 15 | 45 | 55 |
| 16 | 44 | 56 |
| 17 | 43 | 57 |
| 18 | 41 | 59 |
| 19 | 40 | 60 |
| 20 | 39 | 61 |
| 21 | 37 | 63 |
| 22 | 36 | 64 |
| 23 | 36 | 64 |
| 24 | 35 | 65 |
| 25 | 34 | 66 |
| 26 | 34 | 66 |
| 27 | 33 | 67 |
| 28 | 33 | 67 |
| 29 | 33 | 67 |
| 30 | 33 | 67 |
Chance of precipitation in September
Petrópolis gets around 88 mm of rain over 10.7 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 45% on the wettest days. The odds climb 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 (%) | 27 | 27 | 28 | 28 | 29 | 29 | 30 | 30 | 31 | 31 | 32 | 32 | 33 | 33 | 34 | 35 | 35 | 36 | 37 | 38 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 44 | 45 | 45 |
| Rain chance (%) | |
|---|---|
| 1 | 27 |
| 2 | 27 |
| 3 | 28 |
| 4 | 28 |
| 5 | 29 |
| 6 | 29 |
| 7 | 30 |
| 8 | 30 |
| 9 | 31 |
| 10 | 31 |
| 11 | 32 |
| 12 | 32 |
| 13 | 33 |
| 14 | 33 |
| 15 | 34 |
| 16 | 35 |
| 17 | 35 |
| 18 | 36 |
| 19 | 37 |
| 20 | 38 |
| 21 | 38 |
| 22 | 39 |
| 23 | 40 |
| 24 | 41 |
| 25 | 42 |
| 26 | 43 |
| 27 | 44 |
| 28 | 44 |
| 29 | 45 |
| 30 | 45 |
Humidity in September
Most of September feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the humid band about 49% of days. Sticky, muggy-or-worse air turns up on roughly 16% of them.
| 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 (%) | 10 | 10 | 9 | 9 | 9 | 8 | 8 | 7 | 7 | 6 | 6 | 5 | 5 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
| Comfortable (%) | 39 | 38 | 37 | 37 | 36 | 36 | 35 | 34 | 34 | 33 | 32 | 32 | 31 | 30 | 30 | 29 | 28 | 28 | 27 | 26 | 26 | 25 | 24 | 24 | 23 | 22 | 21 | 21 | 20 | 19 |
| Humid (%) | 46 | 46 | 47 | 47 | 48 | 48 | 49 | 49 | 50 | 51 | 51 | 51 | 51 | 52 | 51 | 51 | 52 | 51 | 50 | 50 | 49 | 49 | 48 | 47 | 47 | 46 | 46 | 46 | 45 | 45 |
| Muggy (%) | 6 | 6 | 6 | 7 | 7 | 8 | 8 | 9 | 10 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 16 | 17 | 19 | 20 | 21 | 22 | 23 | 24 | 26 | 27 | 28 | 29 | 30 | 30 |
| Oppressive (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|---|
| 1 | 10 | 39 | 46 | 6 | 0 |
| 2 | 10 | 38 | 46 | 6 | 0 |
| 3 | 9 | 37 | 47 | 6 | 0 |
| 4 | 9 | 37 | 47 | 7 | 0 |
| 5 | 9 | 36 | 48 | 7 | 0 |
| 6 | 8 | 36 | 48 | 8 | 0 |
| 7 | 8 | 35 | 49 | 8 | 0 |
| 8 | 7 | 34 | 49 | 9 | 0 |
| 9 | 7 | 34 | 50 | 10 | 0 |
| 10 | 6 | 33 | 51 | 10 | 0 |
| 11 | 6 | 32 | 51 | 11 | 0 |
| 12 | 5 | 32 | 51 | 12 | 0 |
| 13 | 5 | 31 | 51 | 13 | 0 |
| 14 | 4 | 30 | 52 | 14 | 0 |
| 15 | 4 | 30 | 51 | 15 | 0 |
| 16 | 4 | 29 | 51 | 16 | 0 |
| 17 | 4 | 28 | 52 | 16 | 0 |
| 18 | 4 | 28 | 51 | 17 | 0 |
| 19 | 4 | 27 | 50 | 19 | 0 |
| 20 | 4 | 26 | 50 | 20 | 0 |
| 21 | 4 | 26 | 49 | 21 | 0 |
| 22 | 4 | 25 | 49 | 22 | 0 |
| 23 | 4 | 24 | 48 | 23 | 0 |
| 24 | 4 | 24 | 47 | 24 | 0 |
| 25 | 4 | 23 | 47 | 26 | 0 |
| 26 | 4 | 22 | 46 | 27 | 0 |
| 27 | 4 | 21 | 46 | 28 | 1 |
| 28 | 4 | 21 | 46 | 29 | 1 |
| 29 | 4 | 20 | 45 | 30 | 1 |
| 30 | 4 | 19 | 45 | 30 | 1 |
Wind in September
Winds average 6 km/h in September, the windiest month of the year.
Across September, daily wind ranges from about 6 km/h on the calmest days to 6 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) | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 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 (km/h) | Feels | |
|---|---|---|
| 1 | 6 | calm |
| 2 | 6 | calm |
| 3 | 6 | calm |
| 4 | 6 | calm |
| 5 | 6 | calm |
| 6 | 6 | calm |
| 7 | 6 | calm |
| 8 | 6 | calm |
| 9 | 6 | calm |
| 10 | 6 | calm |
| 11 | 6 | calm |
| 12 | 6 | calm |
| 13 | 6 | 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
Daylight runs from about 11 h 30 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 42 minutes over September. Sunrise moves from 7:06 AM to 6:37 AM, and sunset from 6:39 PM to 6:48 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) | 11.5 | 11.6 | 11.6 | 11.6 | 11.6 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.9 | 11.9 | 11.9 | 11.9 | 12.0 | 12.0 | 12.0 | 12.0 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.2 | 12.2 |
| Sunrise (AM) | 7:06 | 7:05 | 7:04 | 7:03 | 7:02 | 7:01 | 7:00 | 6:59 | 6:58 | 6:57 | 6:56 | 6:55 | 6:54 | 6:53 | 6:52 | 6:51 | 6:50 | 6:49 | 6:48 | 6:47 | 6:46 | 6:45 | 6:44 | 6:43 | 6:42 | 6:41 | 6:40 | 6:39 | 6:38 | 6:37 |
| Sunset (PM) | 6:39 | 6:39 | 6:39 | 6:40 | 6:40 | 6:40 | 6:41 | 6:41 | 6:41 | 6:41 | 6:42 | 6:42 | 6:42 | 6:43 | 6:43 | 6:43 | 6:43 | 6:44 | 6:44 | 6:44 | 6:45 | 6:45 | 6:45 | 6:46 | 6:46 | 6:46 | 6:47 | 6:47 | 6:47 | 6:48 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 11.5 | 7:06 | 6:39 |
| 2 | 11.6 | 7:05 | 6:39 |
| 3 | 11.6 | 7:04 | 6:39 |
| 4 | 11.6 | 7:03 | 6:40 |
| 5 | 11.6 | 7:02 | 6:40 |
| 6 | 11.7 | 7:01 | 6:40 |
| 7 | 11.7 | 7:00 | 6:41 |
| 8 | 11.7 | 6:59 | 6:41 |
| 9 | 11.7 | 6:58 | 6:41 |
| 10 | 11.7 | 6:57 | 6:41 |
| 11 | 11.8 | 6:56 | 6:42 |
| 12 | 11.8 | 6:55 | 6:42 |
| 13 | 11.8 | 6:54 | 6:42 |
| 14 | 11.8 | 6:53 | 6:43 |
| 15 | 11.8 | 6:52 | 6:43 |
| 16 | 11.9 | 6:51 | 6:43 |
| 17 | 11.9 | 6:50 | 6:43 |
| 18 | 11.9 | 6:49 | 6:44 |
| 19 | 11.9 | 6:48 | 6:44 |
| 20 | 12.0 | 6:47 | 6:44 |
| 21 | 12.0 | 6:46 | 6:45 |
| 22 | 12.0 | 6:45 | 6:45 |
| 23 | 12.0 | 6:44 | 6:45 |
| 24 | 12.1 | 6:43 | 6:46 |
| 25 | 12.1 | 6:42 | 6:46 |
| 26 | 12.1 | 6:41 | 6:46 |
| 27 | 12.1 | 6:40 | 6:47 |
| 28 | 12.1 | 6:39 | 6:47 |
| 29 | 12.2 | 6:38 | 6:47 |
| 30 | 12.2 | 6:37 | 6:48 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 4.52 kWh/m².
For context, solar energy here swings from a low near 3.35 kWh/m² to a high of 5.87 kWh/m² in February across the year — September's 4.52 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) | 4.5 | 4.5 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.6 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | 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 | 4.5 | Bright |
| 2 | 4.5 | Bright |
| 3 | 4.6 | Bright |
| 4 | 4.6 | Bright |
| 5 | 4.6 | Bright |
| 6 | 4.6 | Bright |
| 7 | 4.6 | Bright |
| 8 | 4.6 | Bright |
| 9 | 4.6 | Bright |
| 10 | 4.6 | Bright |
| 11 | 4.6 | Bright |
| 12 | 4.6 | Bright |
| 13 | 4.5 | Bright |
| 14 | 4.5 | Bright |
| 15 | 4.5 | Bright |
| 16 | 4.5 | Bright |
| 17 | 4.5 | Bright |
| 18 | 4.5 | Bright |
| 19 | 4.5 | Bright |
| 20 | 4.5 | Bright |
| 21 | 4.5 | Bright |
| 22 | 4.5 | Bright |
| 23 | 4.5 | Bright |
| 24 | 4.5 | Bright |
| 25 | 4.5 | Bright |
| 26 | 4.5 | Bright |
| 27 | 4.5 | Bright |
| 28 | 4.5 | Bright |
| 29 | 4.5 | Bright |
| 30 | 4.6 | Bright |
Hazard calendar for Petrópolis
None of Petrópolis's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.
Petrópolis's rainy season runs November–March, when most of the year's rain falls.
Is September a good time to visit Petrópolis?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a reasonable time to visit Petrópolis for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Petrópolis in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Petrópolis sees daytime highs around 26°C and nights near 17°C. Worth packing: light clothes, rain gear and sun protection. About 11 days see rain.
Sea temperature near Petrópolis in September
The nearest coast averages about 21°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 69 km away) is warmest in March at about 25°C and coldest in August near 21°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 25 | 25 | 25 | 25 | 24 | 23 | 22 | 21 | 21 | 22 | 23 | 24 |
| Comfort | Warm | Warm | Warm | Warm | Refreshing | Refreshing | Refreshing | Refreshing | Refreshing | Refreshing | Refreshing | Warm |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 25 | Warm |
| Feb | 25 | Warm |
| Mar | 25 | Warm |
| Apr | 25 | Warm |
| May | 24 | Refreshing |
| Jun | 23 | Refreshing |
| Jul | 22 | Refreshing |
| Aug | 21 | Refreshing |
| Sep | 21 | Refreshing |
| Oct | 22 | Refreshing |
| Nov | 23 | Refreshing |
| Dec | 24 | Warm |
UV index in Petrópolis in September
Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Petrópolis peaks around January 24 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 at about 6 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 15 | 15 | 13 | 9 | 7 | 6 | 6 | 8 | 7 | 12 | 14 | 14 |
| Level | Extreme | Extreme | Extreme | Very high | High | High | High | Very high | High | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 15 | Extreme |
| Feb | 15 | Extreme |
| Mar | 13 | Extreme |
| Apr | 9 | Very high |
| May | 7 | High |
| Jun | 6 | High |
| Jul | 6 | High |
| Aug | 8 | Very high |
| Sep | 7 | High |
| Oct | 12 | Extreme |
| Nov | 14 | Extreme |
| Dec | 14 | Extreme |
Air quality in Petrópolis in September
Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.
Air quality in Petrópolis is worst in July — around 38 µg/m³ PM2.5 (poor), about 2.0× the cleanest month (December, 19 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) | 19 | 19 | 21 | 24 | 31 | 36 | 38 | 32 | 37 | 24 | 20 | 19 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Poor | Poor | Moderate | Poor | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 19 | Moderate |
| Feb | 19 | Moderate |
| Mar | 21 | Moderate |
| Apr | 24 | Moderate |
| May | 31 | Moderate |
| Jun | 36 | Poor |
| Jul | 38 | Poor |
| Aug | 32 | Moderate |
| Sep | 37 | Poor |
| Oct | 24 | Moderate |
| Nov | 20 | Moderate |
| Dec | 19 | Moderate |
Where is Petrópolis?
Petrópolis sits at 22.5°S, 43.2°W, 819 m above sea level, in Brazil. The nearest listed city is Guapimirim, 21 km away.
Topography around Petrópolis
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Petrópolis.
Within 3 km, the terrain around Petrópolis has large variations in elevation — a maximum elevation change of 611 m around an average of 927 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,242 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,252 m.
The land around Petrópolis is covered by trees (70%) and artificial surfaces (23%) within 3 km, trees (81%) within 16 km, and trees (47%) and grassland (32%) within 80 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
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 Petrópolis (-22.505°, -43.1786°, elevation 819 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. 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).