Alton Weather Forecast 15 Days, Weather in Alton Today
Current weather conditions and 15 day weather forecast for Alton, Illinois, USA including weather daily high/low temperature, warnings, chance of precipitation, pressure, humidity/wind chill, rain risk, wind speed, cloud, pressure, and UV index.
Current weather conditions at Alton
| 11 May 2026 Monday 10.3 ° C / 50.5°F  Clear |
Feels Like : 10.6 ° C / 51°F Humidity : % 75 Pressure : 1022 mb Wind Speed : 3.6 kmph / 2.2 miles from NE  Visibility : 16 km Precipitation (rainfall) : 0 mm Cloud (%) : 0 |
15 day weather forecast for Alton, IL, USA
Weather Forecast for next 15 Days for Alton including weather warnings, temperature, rain, wind speed, cloud, snow, wind speed and wind direction, pressure and UV index.Here is weather for the next 15 days in Alton, Illinois state, US. To see the daily forecast, scroll to the table below.
| Date | Weather forecast | Low temperature | High temperature | Avg. temperature | Humidity | Chance of rain | UV Index | Sun Position | Moon Position | |
|---|---|---|---|---|---|---|---|---|---|---|
| 11 May 2026 Monday | Sunny |
9.2 ° C (48.6°F) |
22 ° C (71.6°F) |
15.6 ° C (60.2°F) |
% 51 | 0% | 7.9 | Sunrise:05:52 AM Sunset: 08:03 PM |
Moonrise:02:50 AM Moonset: 02:22 PM Moon Phase ( Waning Crescent ) |
|
| 12 May 2026 Tuesday |  Patchy rain nearby |
11.7 ° C (53.1°F) |
25.2 ° C (77.3°F) |
18.2 ° C (64.7°F) |
% 69 | 80% | 8 | Sunrise:05:51 AM Sunset: 08:04 PM |
Moonrise:03:14 AM Moonset: 03:30 PM Moon Phase ( Waning Crescent ) |
|
| 13 May 2026 Wednesday | Patchy rain nearby |
11 ° C (51.8°F) |
19.9 ° C (67.8°F) |
15.9 ° C (60.6°F) |
% 70 | 66% | 7.9 | Sunrise:05:50 AM Sunset: 08:05 PM |
Moonrise:03:38 AM Moonset: 04:40 PM Moon Phase ( Waning Crescent ) |
|
| 14 May 2026 Thursday | Sunny |
9.6 ° C (49.4°F) |
22 ° C (71.5°F) |
15.8 ° C (60.5°F) |
% 68 | 0% | 8.4 | Sunrise:05:49 AM Sunset: 08:06 PM |
Moonrise:04:04 AM Moonset: 05:55 PM Moon Phase ( Waning Crescent ) |
|
| 15 May 2026 Friday | Patchy rain nearby |
13.3 ° C (55.9°F) |
25.3 ° C (77.5°F) |
17.5 ° C (63.5°F) |
% 67 | 83% | 0.3 | Sunrise:05:48 AM Sunset: 08:07 PM |
Moonrise:04:34 AM Moonset: 07:13 PM Moon Phase ( Waning Crescent ) |
|
| 16 May 2026 Saturday | Sunny |
18.2 ° C (64.8°F) |
31.5 ° C (88.7°F) |
24.2 ° C (75.5°F) |
% 68 | 0% | 6 | Sunrise:05:47 AM Sunset: 08:08 PM |
Moonrise:05:11 AM Moonset: 08:33 PM Moon Phase ( New Moon ) |
|
| 17 May 2026 Sunday | Patchy rain nearby |
18.9 ° C (66.1°F) |
27.3 ° C (81.1°F) |
22.7 ° C (72.9°F) |
% 74 | 71% | 5 | Sunrise:05:47 AM Sunset: 08:08 PM |
Moonrise:05:58 AM Moonset: 09:51 PM Moon Phase ( Waxing Crescent ) |
|
| 18 May 2026 Monday | Patchy rain nearby |
18.4 ° C (65.2°F) |
27.3 ° C (81.1°F) |
22.2 ° C (71.9°F) |
% 82 | 83% | 5 | Sunrise:05:46 AM Sunset: 08:09 PM |
Moonrise:06:56 AM Moonset: 11:00 PM Moon Phase ( Waxing Crescent ) |
|
| 19 May 2026 Tuesday |  Partly Cloudy |
15.9 ° C (60.6°F) |
22.7 ° C (72.9°F) |
19.3 ° C (66.7°F) |
% 69 | 0% | 5 | Sunrise:05:45 AM Sunset: 08:10 PM |
Moonrise:08:04 AM Moonset: 11:57 PM Moon Phase ( Waxing Crescent ) |
|
| 20 May 2026 Wednesday | Patchy rain nearby |
15.6 ° C (60°F) |
27.5 ° C (81.4°F) |
21.2 ° C (70.2°F) |
% 69 | 75% | 5 | Sunrise:05:44 AM Sunset: 08:11 PM |
Moonrise:09:20 AM Moonset: No moonset Moon Phase ( Waxing Crescent ) |
|
| 21 May 2026 Thursday | Patchy rain nearby |
19 ° C (66.2°F) |
29 ° C (84.1°F) |
23.8 ° C (74.8°F) |
% 82 | 86% | 5 | Sunrise:05:43 AM Sunset: 08:12 PM |
Moonrise:10:35 AM Moonset: 12:41 AM Moon Phase ( Waxing Crescent ) |
|
| 22 May 2026 Friday |  Moderate rain |
18.3 ° C (65°F) |
27 ° C (80.5°F) |
22.1 ° C (71.8°F) |
% 78 | 78% | 5 | Sunrise:05:43 AM Sunset: 08:13 PM |
Moonrise:11:49 AM Moonset: 01:16 AM Moon Phase ( Waxing Crescent ) |
|
| 23 May 2026 Saturday | Sunny |
11.6 ° C (52.9°F) |
23.8 ° C (74.8°F) |
17.9 ° C (64.2°F) |
% 66 | 0% | 5 | Sunrise:05:42 AM Sunset: 08:14 PM |
Moonrise:12:57 PM Moonset: 01:44 AM Moon Phase ( First Quarter ) |
|
| 24 May 2026 Sunday | Moderate rain |
15.8 ° C (60.4°F) |
28.9 ° C (84°F) |
21.1 ° C (70°F) |
% 75 | 82% | 5 | Sunrise:05:41 AM Sunset: 08:14 PM |
Moonrise:02:02 PM Moonset: 02:09 AM Moon Phase ( Waxing Gibbous ) |
|
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