Keystone weather in April
In April, Keystone sees average daytime highs of 82°F and overnight lows near 63°F, with 2.1 in of rain across 6 wet days and about 12.7 hours of daylight. It is the 7th-warmest and 10th-wettest month of the year here.
Highs climb over the month, from about 80°F in the first days to 84°F by the end. The sky is clear or mostly clear about 47% of the time in April, and the air most often feels dry.
Daylight stretches from about 12 h 18 min at the start of April to 13 hours by month's end. Set against the rest of the year, April is Keystone's 2nd-clearest and 5th-windiest month. For the whole year in context, see Keystone's year-round climate.
- Daytime high
- 82°
- 7th warmest
- Overnight low
- 63°
- 6th coldest
- Rainfall
- 2.1 in
- 6 wet days
- Daylight
- 12 h 42 min
- 6:11 AM – 6:51 PM
- Cloud cover
- 46%
- 2nd clearest
- Wind
- 7 mph
- 5th windiest
- Solar energy
- 6.17 kWh/m²
- Travel score
- 7.0
- out of 10
Keystone is census-designated place in Hillsborough County, Florida, United States.
- Density
- 237/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in April
Highs climb over the month, from about 80°F in the first days to 84°F by the end.
A typical April day in Keystone reaches about 82°F in the afternoon and slips back to 63°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 74°F and 87°F. Set against its neighbours, April runs about 5°F warmer than March and about 5°F cooler than May.
| 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 (°F) | 79 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 81 | 81 | 81 | 81 | 81 | 81 | 81 | 82 | 82 | 82 | 82 | 82 | 82 | 82 | 83 | 83 | 83 | 83 | 83 | 84 | 84 | 84 |
| Avg low (°F) | 60 | 60 | 60 | 61 | 61 | 61 | 61 | 61 | 62 | 62 | 62 | 62 | 62 | 62 | 62 | 63 | 63 | 63 | 63 | 63 | 64 | 64 | 64 | 64 | 64 | 64 | 65 | 65 | 65 | 65 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 79 | 60 |
| 2 | 80 | 60 |
| 3 | 80 | 60 |
| 4 | 80 | 61 |
| 5 | 80 | 61 |
| 6 | 80 | 61 |
| 7 | 80 | 61 |
| 8 | 80 | 61 |
| 9 | 81 | 62 |
| 10 | 81 | 62 |
| 11 | 81 | 62 |
| 12 | 81 | 62 |
| 13 | 81 | 62 |
| 14 | 81 | 62 |
| 15 | 81 | 62 |
| 16 | 82 | 63 |
| 17 | 82 | 63 |
| 18 | 82 | 63 |
| 19 | 82 | 63 |
| 20 | 82 | 63 |
| 21 | 82 | 64 |
| 22 | 82 | 64 |
| 23 | 83 | 64 |
| 24 | 83 | 64 |
| 25 | 83 | 64 |
| 26 | 83 | 64 |
| 27 | 83 | 65 |
| 28 | 84 | 65 |
| 29 | 84 | 65 |
| 30 | 84 | 65 |
How April really feels in Keystone
Once humidity and wind are folded in, April averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
April sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Keystone weather by month
How April compares with the rest of the year at a glance. April is the 7th-warmest and 10th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 69° / 51° | 2.5 | 6.5 | 10.4 | 7.1 |
| Feb | 72° / 53° | 2.2 | 6.3 | 11 | 7.4 |
| Mar | 76° / 57° | 2.5 | 6.3 | 11.8 | 7.7 |
| Apr | 82° / 63° | 2.1 | 6 | 12.7 | 7.0 |
| May | 87° / 69° | 2.3 | 7.3 | 13.4 | 5.3 |
| Jun | 89° / 74° | 5.0 | 16.4 | 13.8 | 3.6 |
| Jul | 89° / 76° | 5.0 | 18.3 | 13.6 | 3.2 |
| Aug | 89° / 76° | 5.6 | 19.8 | 13 | 3.1 |
| Sep | 88° / 74° | 4.6 | 14.7 | 12.2 | 3.8 |
| Oct | 84° / 67° | 2.1 | 7.2 | 11.3 | 6.2 |
| Nov | 77° / 58° | 1.4 | 4.3 | 10.6 | 7.9 |
| Dec | 72° / 54° | 2.2 | 6 | 10.2 | 7.5 |
Cloud cover in April
The sky is clear or mostly clear about 47% of the time in April.
Beyond those clear spells, partly cloudy skies cover about 17% of April, with mostly cloudy or overcast conditions the remaining 36%.
| 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 (%) | 64 | 64 | 63 | 63 | 63 | 63 | 63 | 62 | 62 | 62 | 62 | 61 | 61 | 61 | 62 | 62 | 63 | 63 | 64 | 64 | 65 | 64 | 64 | 65 | 65 | 66 | 67 | 67 | 68 | 68 |
| Cloudier (%) | 36 | 36 | 37 | 37 | 37 | 37 | 37 | 38 | 38 | 38 | 38 | 39 | 39 | 39 | 38 | 38 | 37 | 37 | 36 | 36 | 35 | 36 | 36 | 35 | 35 | 34 | 33 | 33 | 32 | 32 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 64 | 36 |
| 2 | 64 | 36 |
| 3 | 63 | 37 |
| 4 | 63 | 37 |
| 5 | 63 | 37 |
| 6 | 63 | 37 |
| 7 | 63 | 37 |
| 8 | 62 | 38 |
| 9 | 62 | 38 |
| 10 | 62 | 38 |
| 11 | 62 | 38 |
| 12 | 61 | 39 |
| 13 | 61 | 39 |
| 14 | 61 | 39 |
| 15 | 62 | 38 |
| 16 | 62 | 38 |
| 17 | 63 | 37 |
| 18 | 63 | 37 |
| 19 | 64 | 36 |
| 20 | 64 | 36 |
| 21 | 65 | 35 |
| 22 | 64 | 36 |
| 23 | 64 | 36 |
| 24 | 65 | 35 |
| 25 | 65 | 35 |
| 26 | 66 | 34 |
| 27 | 67 | 33 |
| 28 | 67 | 33 |
| 29 | 68 | 32 |
| 30 | 68 | 32 |
Chance of precipitation in April
Keystone gets around 2.1 in of rain over 6 wet days in April. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 20% and peaks near 21% 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 (%) | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 19 | 19 |
| Rain chance (%) | |
|---|---|
| 1 | 21 |
| 2 | 21 |
| 3 | 21 |
| 4 | 21 |
| 5 | 21 |
| 6 | 21 |
| 7 | 21 |
| 8 | 21 |
| 9 | 21 |
| 10 | 21 |
| 11 | 21 |
| 12 | 21 |
| 13 | 21 |
| 14 | 21 |
| 15 | 20 |
| 16 | 20 |
| 17 | 20 |
| 18 | 20 |
| 19 | 20 |
| 20 | 20 |
| 21 | 20 |
| 22 | 20 |
| 23 | 20 |
| 24 | 20 |
| 25 | 20 |
| 26 | 20 |
| 27 | 20 |
| 28 | 20 |
| 29 | 19 |
| 30 | 19 |
Humidity in April
Most of April feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, April lands in the dry band about 29% of days. Sticky, muggy-or-worse air turns up on roughly 26% 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 (%) | 35 | 35 | 34 | 34 | 33 | 33 | 33 | 32 | 32 | 32 | 32 | 32 | 31 | 31 | 31 | 30 | 30 | 29 | 29 | 28 | 28 | 27 | 26 | 26 | 25 | 24 | 23 | 23 | 22 | 21 |
| Comfortable (%) | 20 | 20 | 20 | 20 | 19 | 19 | 19 | 19 | 20 | 20 | 20 | 20 | 21 | 21 | 21 | 22 | 22 | 22 | 23 | 23 | 23 | 23 | 22 | 22 | 22 | 21 | 21 | 21 | 20 | 20 |
| Humid (%) | 24 | 24 | 25 | 25 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 25 | 25 | 25 | 24 | 24 | 23 | 23 | 23 | 22 | 22 | 22 | 22 | 22 | 22 | 23 | 23 | 23 | 23 | 24 |
| Muggy (%) | 19 | 19 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 21 | 21 | 21 | 21 | 22 | 22 | 22 | 23 | 23 | 23 | 24 | 24 | 25 | 25 | 26 | 27 | 27 | 28 | 28 | 28 |
| Oppressive (%) | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 5 | 6 | 6 | 7 | 7 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|---|
| 1 | 35 | 20 | 24 | 19 | 1 |
| 2 | 35 | 20 | 24 | 19 | 1 |
| 3 | 34 | 20 | 25 | 20 | 1 |
| 4 | 34 | 20 | 25 | 20 | 1 |
| 5 | 33 | 19 | 26 | 20 | 1 |
| 6 | 33 | 19 | 26 | 20 | 2 |
| 7 | 33 | 19 | 26 | 20 | 2 |
| 8 | 32 | 19 | 26 | 20 | 2 |
| 9 | 32 | 20 | 26 | 20 | 2 |
| 10 | 32 | 20 | 26 | 20 | 2 |
| 11 | 32 | 20 | 26 | 21 | 2 |
| 12 | 32 | 20 | 25 | 21 | 2 |
| 13 | 31 | 21 | 25 | 21 | 2 |
| 14 | 31 | 21 | 25 | 21 | 2 |
| 15 | 31 | 21 | 24 | 22 | 2 |
| 16 | 30 | 22 | 24 | 22 | 2 |
| 17 | 30 | 22 | 23 | 22 | 3 |
| 18 | 29 | 22 | 23 | 23 | 3 |
| 19 | 29 | 23 | 23 | 23 | 3 |
| 20 | 28 | 23 | 22 | 23 | 3 |
| 21 | 28 | 23 | 22 | 24 | 3 |
| 22 | 27 | 23 | 22 | 24 | 4 |
| 23 | 26 | 22 | 22 | 25 | 4 |
| 24 | 26 | 22 | 22 | 25 | 4 |
| 25 | 25 | 22 | 22 | 26 | 5 |
| 26 | 24 | 21 | 23 | 27 | 5 |
| 27 | 23 | 21 | 23 | 27 | 6 |
| 28 | 23 | 21 | 23 | 28 | 6 |
| 29 | 22 | 20 | 23 | 28 | 7 |
| 30 | 21 | 20 | 24 | 28 | 7 |
Wind in April
Winds average 7 mph in April.
Across April, daily wind ranges from about 7 mph on the calmest days to 7 mph 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 (mph) | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 |
| 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 (mph) | 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 | 7 | calm |
| 15 | 7 | calm |
| 16 | 7 | calm |
| 17 | 7 | calm |
| 18 | 7 | calm |
| 19 | 7 | calm |
| 20 | 7 | calm |
| 21 | 7 | calm |
| 22 | 7 | calm |
| 23 | 7 | calm |
| 24 | 7 | calm |
| 25 | 7 | calm |
| 26 | 7 | calm |
| 27 | 7 | calm |
| 28 | 7 | calm |
| 29 | 7 | calm |
| 30 | 7 | calm |
Sunrise & sunset in April
Daylight runs from about 12 h 18 min at the start of April to 13 hours by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 42 minutes over April. Sunrise moves from 6:28 AM to 5:57 AM, and sunset from 6:43 PM to 6:59 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) | 12.3 | 12.3 | 12.3 | 12.3 | 12.4 | 12.4 | 12.4 | 12.5 | 12.5 | 12.5 | 12.5 | 12.6 | 12.6 | 12.6 | 12.6 | 12.7 | 12.7 | 12.7 | 12.8 | 12.8 | 12.8 | 12.8 | 12.9 | 12.9 | 12.9 | 12.9 | 13.0 | 13.0 | 13.0 | 13.0 |
| Sunrise (AM) | 6:28 | 6:26 | 6:25 | 6:24 | 6:23 | 6:22 | 6:21 | 6:19 | 6:18 | 6:17 | 6:16 | 6:15 | 6:14 | 6:13 | 6:12 | 6:11 | 6:09 | 6:08 | 6:07 | 6:06 | 6:05 | 6:04 | 6:03 | 6:02 | 6:01 | 6:00 | 5:59 | 5:59 | 5:58 | 5:57 |
| Sunset (PM) | 6:43 | 6:43 | 6:44 | 6:44 | 6:45 | 6:45 | 6:46 | 6:46 | 6:47 | 6:48 | 6:48 | 6:49 | 6:49 | 6:50 | 6:50 | 6:51 | 6:51 | 6:52 | 6:53 | 6:53 | 6:54 | 6:54 | 6:55 | 6:55 | 6:56 | 6:57 | 6:57 | 6:58 | 6:58 | 6:59 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.3 | 6:28 | 6:43 |
| 2 | 12.3 | 6:26 | 6:43 |
| 3 | 12.3 | 6:25 | 6:44 |
| 4 | 12.3 | 6:24 | 6:44 |
| 5 | 12.4 | 6:23 | 6:45 |
| 6 | 12.4 | 6:22 | 6:45 |
| 7 | 12.4 | 6:21 | 6:46 |
| 8 | 12.5 | 6:19 | 6:46 |
| 9 | 12.5 | 6:18 | 6:47 |
| 10 | 12.5 | 6:17 | 6:48 |
| 11 | 12.5 | 6:16 | 6:48 |
| 12 | 12.6 | 6:15 | 6:49 |
| 13 | 12.6 | 6:14 | 6:49 |
| 14 | 12.6 | 6:13 | 6:50 |
| 15 | 12.6 | 6:12 | 6:50 |
| 16 | 12.7 | 6:11 | 6:51 |
| 17 | 12.7 | 6:09 | 6:51 |
| 18 | 12.7 | 6:08 | 6:52 |
| 19 | 12.8 | 6:07 | 6:53 |
| 20 | 12.8 | 6:06 | 6:53 |
| 21 | 12.8 | 6:05 | 6:54 |
| 22 | 12.8 | 6:04 | 6:54 |
| 23 | 12.9 | 6:03 | 6:55 |
| 24 | 12.9 | 6:02 | 6:55 |
| 25 | 12.9 | 6:01 | 6:56 |
| 26 | 12.9 | 6:00 | 6:57 |
| 27 | 13.0 | 5:59 | 6:57 |
| 28 | 13.0 | 5:59 | 6:58 |
| 29 | 13.0 | 5:58 | 6:58 |
| 30 | 13.0 | 5:57 | 6:59 |
Solar energy in April
Average shortwave solar energy reaching the ground each day in April, about 6.17 kWh/m².
For context, solar energy here swings from a low near 3.15 kWh/m² to a high of 6.46 kWh/m² in May across the year — April's 6.17 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) | 5.8 | 5.8 | 5.8 | 5.9 | 5.9 | 5.9 | 5.9 | 6.0 | 6.0 | 6.0 | 6.0 | 6.0 | 6.1 | 6.1 | 6.1 | 6.2 | 6.2 | 6.2 | 6.2 | 6.3 | 6.3 | 6.3 | 6.3 | 6.3 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.5 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.8 | Bright |
| 2 | 5.8 | Bright |
| 3 | 5.8 | Bright |
| 4 | 5.9 | Bright |
| 5 | 5.9 | Bright |
| 6 | 5.9 | Bright |
| 7 | 5.9 | Bright |
| 8 | 6.0 | Bright |
| 9 | 6.0 | Bright |
| 10 | 6.0 | Intense |
| 11 | 6.0 | Intense |
| 12 | 6.0 | Intense |
| 13 | 6.1 | Intense |
| 14 | 6.1 | Intense |
| 15 | 6.1 | Intense |
| 16 | 6.2 | Intense |
| 17 | 6.2 | Intense |
| 18 | 6.2 | Intense |
| 19 | 6.2 | Intense |
| 20 | 6.3 | Intense |
| 21 | 6.3 | Intense |
| 22 | 6.3 | Intense |
| 23 | 6.3 | Intense |
| 24 | 6.3 | Intense |
| 25 | 6.4 | Intense |
| 26 | 6.4 | Intense |
| 27 | 6.4 | Intense |
| 28 | 6.4 | Intense |
| 29 | 6.4 | Intense |
| 30 | 6.5 | Intense |
Hazard calendar for Keystone
None of Keystone's seasonal hazards are active in April. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.
Keystone sits in the Atlantic hurricane belt; the season peaks August–October.
Keystone's rainy season runs June–September, when most of the year's rain falls.
Is April a good time to visit Keystone?
Our two travel scores rate April for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
April is one of the better times to visit Keystone for general sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Keystone in April
From April's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In April, Keystone sees daytime highs around 82°F and nights near 63°F. Pack light clothes and sun protection. About 6 days see rain.
Sea temperature near Keystone in April
The nearest coast averages about 73°F in April — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 16 mi away) is warmest in August at about 86°F and coldest in February near 63°F.
It's comfortable for a long swim from Mar 21 to Dec 11 — about 8.7 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 64 | 63 | 67 | 73 | 78 | 83 | 85 | 86 | 84 | 80 | 73 | 67 |
| Comfort | Cool | Cool | Cool | Refreshing | Warm | Tropical | Tropical | Tropical | Tropical | Warm | Refreshing | Cool |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 64 | Cool |
| Feb | 63 | Cool |
| Mar | 67 | Cool |
| Apr | 73 | Refreshing |
| May | 78 | Warm |
| Jun | 83 | Tropical |
| Jul | 85 | Tropical |
| Aug | 86 | Tropical |
| Sep | 84 | Tropical |
| Oct | 80 | Warm |
| Nov | 73 | Refreshing |
| Dec | 67 | Cool |
UV index in Keystone in April
Clear-sky midday UV in April peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Keystone peaks around July 12 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 4 (moderate).
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) | 5 | 7 | 8 | 9 | 9 | 11 | 11 | 10 | 9 | 7 | 5 | 4 |
| Level | Moderate | High | Very high | Very high | Very high | Extreme | Extreme | Very high | Very high | Very high | High | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 5 | Moderate |
| Feb | 7 | High |
| Mar | 8 | Very high |
| Apr | 9 | Very high |
| May | 9 | Very high |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 10 | Very high |
| Sep | 9 | Very high |
| Oct | 7 | Very high |
| Nov | 5 | High |
| Dec | 4 | Moderate |
Air quality in Keystone in April
Average fine-particle pollution (PM2.5) through the year — so you can see where April falls, not just the annual average.
Air quality in Keystone is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (November, 9 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) | 9 | 10 | 10 | 11 | 11 | 16 | 18 | 17 | 12 | 9 | 9 | 9 |
| Level | Good | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 9 | Good |
| Feb | 10 | Good |
| Mar | 10 | Good |
| Apr | 11 | Good |
| May | 11 | Good |
| Jun | 16 | Moderate |
| Jul | 18 | Moderate |
| Aug | 17 | Moderate |
| Sep | 12 | Moderate |
| Oct | 9 | Good |
| Nov | 9 | Good |
| Dec | 9 | Good |
Where is Keystone?
Keystone sits at 28.2°N, 82.6°W, 39 ft above sea level, in United States. The nearest listed city is East Lake, 5.6 mi away.
Topography around Keystone
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Keystone.
Within 2 miles, the terrain around Keystone has only modest variations in elevation — a maximum elevation change of 98 ft around an average of 49 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 138 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 374 ft.
The land around Keystone is covered by trees (46%) and grassland (39%) within 2 miles, trees (56%) and artificial surfaces (20%) within 10 miles, and trees (39%) and water (37%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- 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 Keystone (28.1559°, -82.6212°, elevation 39 ft), 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).