Mystic, CT weather in August
Mystic is warm and often humid in August, with some rain: highs average 80°F and nights drop to about 65°F. Rain falls on about 9 days. This is the peak of the warm season in Mystic.
- Normal high
- 80°F
- Normal low
- 65°F
- Wet days
- 9
- 4.2 in total
- Muggy days
- 14
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 81°F | 78°F |
| Normal low | 66°F | 63°F |
| Chance of a wet day | 32% | 30% |
| Sunrise / sunset | 5:43 am / 8:05 pm | 6:13 am / 7:23 pm |
| Daylight | 14.4 h | 13.2 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical August day
- 6 am67°Fdew point 62°F
- 9 am75°Fdew point 62°F
- Noon79°Fdew point 61°F
- 3 pm80°Fdew point 62°F
- 6 pm75°Fdew point 62°F
- 9 pm70°Fdew point 63°F
NOAA hourly normals (local standard time) from Providence T F Green Airport (38 mi away); average wind 8 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°Fnot available
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph12 of 31
- Hot dayshigh 90°F or more1 of 31
- Muggy daysdaily mean dew point 65°F or more14 of 31
- Wet daysat least 0.01 in of rain or melted snow9 of 31
- Notable rainat least 0.10 in6 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 4.2 in; a dry August brings about 2.5 in and a wet one about 5.4 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How August varies from year to year
- Warmest August, 1991-20202016: average high 83°F
- Coolest August1996: average high 76°F
- Wettest August1991: 11.6 in
- Driest August2017: 1.6 in
- Highest reading96°F (August 31, 2010)
- Lowest reading48°F (August 19, 1991)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 81°F | 80°F | 74°F |
| Normal low | 66°F | 65°F | 58°F |
| Wet days | 10 | 9 | 10 |
| Comfortable days | – | – | – |
| Daylight | 14.8 h | 13.8 h | 12.5 h |
Highs change by -1°F from July and -6°F into September.
Nearby alternatives in August
- Warmer: Paterson, NJ119 mi · high 85°F · 10 wet days
- Cooler: Lake Placid, NY226 mi · high 73°F · 13 wet days
How Mystic ranks in August
- Normal high312th warmest of 378 cities; 5th of 5 in Connecticut
- Wet days202nd driest of 378
What to pack for Mystic in August
- A rain jacket or umbrella – rain on about 9 days
- A swimsuit – about 12 beach days
Heating and cooling
August has 3 heating degree days and 234 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Mystic in August?
The normal high is 80°F and the normal low is 65°F. From 1991 to 2020 the hottest August reading was 96°F (August 31, 2010).
Does it rain a lot in Mystic in August?
About 9 days in August have at least 0.01 in of precipitation, and the normal total is 4.2 in. The wettest August in 1991-2020 was in 1991 (11.6 in); the driest was in 2017 (1.6 in).
Where the numbers come from
- Temperature, rain, snowfall and snow depth: Groton (USC00063207), 3.7 mi W of the city center, 40 ft . NOAA normals and daily records, 1991-2020.
- Frost dates: Groton New London Airport (USW00014707), 4.7 mi WSW of the city center, 10 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Providence T F Green Airport (USW00014765), 38 mi NE of the city center, 60 ft (52 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Groton-New London Airport (725046-14707), 4.7 mi WSW of the city center, 8 ft . Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).