Pupiales weather in September
In September, Pupiales sees average daytime highs of 15°C and overnight lows near 6°C, with 109 mm of rain across 21.9 wet days and about 12 hours of daylight. It is the 8th-warmest and 11th-wettest month of the year here.
Day-to-day highs hold fairly steady near 15°C through the month. The sky is clear or mostly clear about 2% of the time in September, and the air most often feels dry.
Daylight stretches from about 12 hours at the start of September to 12 hours by month's end. Set against the rest of the year, September is Pupiales's 2nd-clearest and 4th-windiest month. For the whole year in context, see Pupiales's year-round climate.
- Daytime high
- 15°
- 8th warmest
- Overnight low
- 6°
- 3rd coldest
- Rainfall
- 109 mm
- 21.9 wet days
- Daylight
- 12 hours
- 6:05 AM – 6:05 PM
- Cloud cover
- 84%
- 2nd clearest
- Wind
- 6 km/h
- 4th windiest
- Solar energy
- 5.1 kWh/m²
- Travel score
- 2.9
- out of 10
Temperature in September
Day-to-day highs hold fairly steady near 15°C through the month.
A typical September day in Pupiales reaches about 15°C in the afternoon and slips back to 6°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 16°C. Set against its neighbours, September runs about 1°C warmer than August and on par with 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) | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 |
| Avg low (°C) | 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 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 14 | 6 |
| 2 | 14 | 6 |
| 3 | 14 | 6 |
| 4 | 14 | 6 |
| 5 | 14 | 6 |
| 6 | 14 | 6 |
| 7 | 14 | 6 |
| 8 | 14 | 6 |
| 9 | 14 | 6 |
| 10 | 14 | 6 |
| 11 | 14 | 6 |
| 12 | 14 | 6 |
| 13 | 15 | 6 |
| 14 | 15 | 6 |
| 15 | 15 | 6 |
| 16 | 15 | 6 |
| 17 | 15 | 6 |
| 18 | 15 | 6 |
| 19 | 15 | 6 |
| 20 | 15 | 6 |
| 21 | 15 | 6 |
| 22 | 15 | 6 |
| 23 | 15 | 6 |
| 24 | 15 | 6 |
| 25 | 15 | 6 |
| 26 | 15 | 6 |
| 27 | 15 | 6 |
| 28 | 15 | 6 |
| 29 | 15 | 6 |
| 30 | 15 | 6 |
Pupiales weather by month
How September compares with the rest of the year at a glance. September is the 8th-warmest and 11th-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 15° / 7° | 220 | 27.5 | 12 | 2.6 |
| Feb | 15° / 7° | 205 | 24.9 | 12 | 2.6 |
| Mar | 15° / 7° | 251 | 29.4 | 12 | 2.4 |
| Apr | 15° / 7° | 258 | 29.2 | 12 | 2.3 |
| May | 14° / 7° | 200 | 29.8 | 12 | 2.3 |
| Jun | 14° / 6° | 160 | 27.4 | 12 | 2.2 |
| Jul | 13° / 6° | 147 | 27 | 12 | 2.2 |
| Aug | 14° / 6° | 94 | 22.7 | 12 | 2.6 |
| Sep | 15° / 6° | 109 | 21.9 | 12 | 2.9 |
| Oct | 15° / 7° | 230 | 27.4 | 12 | 2.7 |
| Nov | 15° / 7° | 290 | 28 | 12 | 2.5 |
| Dec | 15° / 7° | 269 | 29.1 | 12 | 2.5 |
Cloud cover in September
The sky is clear or mostly clear about 2% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 6% of September, with mostly cloudy or overcast conditions the remaining 92%.
| 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 (%) | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 10 | 10 | 10 | 10 | 9 | 9 | 9 | 9 | 8 | 7 | 7 | 7 | 6 | 6 | 6 | 6 | 6 | 5 | 5 | 5 | 5 |
| Cloudier (%) | 91 | 91 | 91 | 91 | 91 | 91 | 91 | 91 | 91 | 90 | 90 | 90 | 90 | 91 | 91 | 91 | 91 | 92 | 93 | 93 | 93 | 94 | 94 | 94 | 94 | 94 | 95 | 95 | 95 | 95 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 9 | 91 |
| 2 | 9 | 91 |
| 3 | 9 | 91 |
| 4 | 9 | 91 |
| 5 | 9 | 91 |
| 6 | 9 | 91 |
| 7 | 9 | 91 |
| 8 | 9 | 91 |
| 9 | 9 | 91 |
| 10 | 10 | 90 |
| 11 | 10 | 90 |
| 12 | 10 | 90 |
| 13 | 10 | 90 |
| 14 | 9 | 91 |
| 15 | 9 | 91 |
| 16 | 9 | 91 |
| 17 | 9 | 91 |
| 18 | 8 | 92 |
| 19 | 7 | 93 |
| 20 | 7 | 93 |
| 21 | 7 | 93 |
| 22 | 6 | 94 |
| 23 | 6 | 94 |
| 24 | 6 | 94 |
| 25 | 6 | 94 |
| 26 | 6 | 94 |
| 27 | 5 | 95 |
| 28 | 5 | 95 |
| 29 | 5 | 95 |
| 30 | 5 | 95 |
Chance of precipitation in September
Pupiales gets around 109 mm of rain over 21.9 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 73% and peaks near 82% 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 (%) | 67 | 67 | 67 | 67 | 68 | 68 | 68 | 69 | 69 | 69 | 70 | 70 | 70 | 71 | 71 | 72 | 73 | 73 | 74 | 75 | 75 | 76 | 77 | 77 | 78 | 79 | 80 | 80 | 81 | 82 |
| Rain chance (%) | |
|---|---|
| 1 | 67 |
| 2 | 67 |
| 3 | 67 |
| 4 | 67 |
| 5 | 68 |
| 6 | 68 |
| 7 | 68 |
| 8 | 69 |
| 9 | 69 |
| 10 | 69 |
| 11 | 70 |
| 12 | 70 |
| 13 | 70 |
| 14 | 71 |
| 15 | 71 |
| 16 | 72 |
| 17 | 73 |
| 18 | 73 |
| 19 | 74 |
| 20 | 75 |
| 21 | 75 |
| 22 | 76 |
| 23 | 77 |
| 24 | 77 |
| 25 | 78 |
| 26 | 79 |
| 27 | 80 |
| 28 | 80 |
| 29 | 81 |
| 30 | 82 |
Humidity in September
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 6 km/h in September.
Across September, daily wind ranges from about 6 km/h on the calmest days to 7 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) | 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 (km/h) | 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
Daylight runs from about 12 hours at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 0 minutes over September. Sunrise moves from 6:10 AM to 6:00 AM, and sunset from 6:11 PM to 6:00 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) | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 |
| Sunrise (AM) | 6:10 | 6:09 | 6:09 | 6:09 | 6:08 | 6:08 | 6:08 | 6:08 | 6:07 | 6:07 | 6:06 | 6:06 | 6:06 | 6:05 | 6:05 | 6:05 | 6:04 | 6:04 | 6:04 | 6:03 | 6:03 | 6:03 | 6:02 | 6:02 | 6:02 | 6:01 | 6:01 | 6:01 | 6:00 | 6:00 |
| Sunset (PM) | 6:11 | 6:10 | 6:10 | 6:10 | 6:09 | 6:09 | 6:09 | 6:08 | 6:08 | 6:07 | 6:07 | 6:07 | 6:06 | 6:06 | 6:05 | 6:05 | 6:05 | 6:04 | 6:04 | 6:03 | 6:03 | 6:03 | 6:02 | 6:02 | 6:02 | 6:01 | 6:01 | 6:00 | 6:00 | 6:00 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.0 | 6:10 | 6:11 |
| 2 | 12.0 | 6:09 | 6:10 |
| 3 | 12.0 | 6:09 | 6:10 |
| 4 | 12.0 | 6:09 | 6:10 |
| 5 | 12.0 | 6:08 | 6:09 |
| 6 | 12.0 | 6:08 | 6:09 |
| 7 | 12.0 | 6:08 | 6:09 |
| 8 | 12.0 | 6:08 | 6:08 |
| 9 | 12.0 | 6:07 | 6:08 |
| 10 | 12.0 | 6:07 | 6:07 |
| 11 | 12.0 | 6:06 | 6:07 |
| 12 | 12.0 | 6:06 | 6:07 |
| 13 | 12.0 | 6:06 | 6:06 |
| 14 | 12.0 | 6:05 | 6:06 |
| 15 | 12.0 | 6:05 | 6:05 |
| 16 | 12.0 | 6:05 | 6:05 |
| 17 | 12.0 | 6:04 | 6:05 |
| 18 | 12.0 | 6:04 | 6:04 |
| 19 | 12.0 | 6:04 | 6:04 |
| 20 | 12.0 | 6:03 | 6:03 |
| 21 | 12.0 | 6:03 | 6:03 |
| 22 | 12.0 | 6:03 | 6:03 |
| 23 | 12.0 | 6:02 | 6:02 |
| 24 | 12.0 | 6:02 | 6:02 |
| 25 | 12.0 | 6:02 | 6:02 |
| 26 | 12.0 | 6:01 | 6:01 |
| 27 | 12.0 | 6:01 | 6:01 |
| 28 | 12.0 | 6:01 | 6:00 |
| 29 | 12.0 | 6:00 | 6:00 |
| 30 | 12.0 | 6:00 | 6:00 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 5.1 kWh/m² — the sunniest month for solar.
For context, solar energy here swings from a low near 4.18 kWh/m² to a high of 5.1 kWh/m² in September across the year — September's 5.1 kWh/m² sits near the top of that range.
| 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) | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.0 | 5.0 | 5.0 | 5.0 |
| 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 | 5.1 | Bright |
| 2 | 5.1 | Bright |
| 3 | 5.1 | Bright |
| 4 | 5.1 | Bright |
| 5 | 5.1 | Bright |
| 6 | 5.1 | Bright |
| 7 | 5.1 | Bright |
| 8 | 5.1 | Bright |
| 9 | 5.1 | Bright |
| 10 | 5.1 | Bright |
| 11 | 5.1 | Bright |
| 12 | 5.1 | Bright |
| 13 | 5.1 | Bright |
| 14 | 5.1 | Bright |
| 15 | 5.1 | Bright |
| 16 | 5.1 | Bright |
| 17 | 5.1 | Bright |
| 18 | 5.1 | Bright |
| 19 | 5.1 | Bright |
| 20 | 5.1 | Bright |
| 21 | 5.1 | Bright |
| 22 | 5.1 | Bright |
| 23 | 5.1 | Bright |
| 24 | 5.1 | Bright |
| 25 | 5.1 | Bright |
| 26 | 5.1 | Bright |
| 27 | 5.0 | Bright |
| 28 | 5.0 | Bright |
| 29 | 5.0 | Bright |
| 30 | 5.0 | Bright |
Is September a good time to visit Pupiales?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a weaker month for outdoor sightseeing in Pupiales.
What to pack for Pupiales in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Pupiales sees daytime highs around 15°C and nights near 6°C. Pack rain gear. Worth having: a warm layer and sun protection. About 22 days see rain.
UV index in Pupiales in September
Clear-sky midday UV in September peaks around 15 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Pupiales peaks around February 22 at about 18 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 20 at about 13 (extreme).
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) | 17 | 18 | 18 | 16 | 16 | 14 | 13 | 13 | 15 | 15 | 14 | 14 |
| Level | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 17 | Extreme |
| Feb | 18 | Extreme |
| Mar | 18 | Extreme |
| Apr | 16 | Extreme |
| May | 16 | Extreme |
| Jun | 14 | Extreme |
| Jul | 13 | Extreme |
| Aug | 13 | Extreme |
| Sep | 15 | Extreme |
| Oct | 15 | Extreme |
| Nov | 14 | Extreme |
| Dec | 14 | Extreme |
Air quality in Pupiales 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 Pupiales is worst in September — around 19 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (June, 10 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) | 11 | 13 | 14 | 13 | 11 | 10 | 10 | 13 | 19 | 12 | 11 | 12 |
| Level | Good | Moderate | Moderate | Moderate | Good | Good | Good | Moderate | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 11 | Good |
| Feb | 13 | Moderate |
| Mar | 14 | Moderate |
| Apr | 13 | Moderate |
| May | 11 | Good |
| Jun | 10 | Good |
| Jul | 10 | Good |
| Aug | 13 | Moderate |
| Sep | 19 | Moderate |
| Oct | 12 | Moderate |
| Nov | 11 | Good |
| Dec | 12 | Good |
Where is Pupiales?
Pupiales sits at 0.9°N, 77.6°W, 2,974 m above sea level, in Colombia. The nearest listed city is Ipiales, 5.0 km away.
Topography around Pupiales
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Pupiales.
Within 3 km, the terrain around Pupiales has only modest variations in elevation — a maximum elevation change of 248 m around an average of 2,952 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,382 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,555 m.
The land around Pupiales is covered by grassland (38%), trees (36%) and cropland (23%) within 3 km, trees (46%) and grassland (41%) within 16 km, and trees (74%) and grassland (23%) within 80 km.
Colombia travel facts
- Travel advisory
- Level 3
- Reconsider Travel
- Power plugs
- Type A / B
- 120 / 240 V · 60 Hz
- Prices
- ≈ 38% of US
- price level, 2025
- GDP per capita
- $8,562
- 2025
- Happiness
- 6.0 / 10
- World Happiness, 2025
- Safe drinking water
- 74%
- of population, 2024
- Homicide rate
- 24.9
- per 100k, 2023
- Road deaths
- 15.4
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Low
- EF EPI 480
- 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 Pupiales (0.8714°, -77.6403°, elevation 2,974 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).