Islip weather by month & the best time to visit
🇺🇸 United States · seaside town · humid subtropical climate
The best time to visit Islip is July — its sunniest month (Sunshine Score 75/100), with September and August close behind. Islip averages about 2,252 hours of sunshine a year. Daytime highs around 27°C / 81°F and roughly 95 mm of rain in July.
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- Sun hours / year
- 2,252
- Sunniest month
- July
- Peak score
- 75/100
- Rain / year
- 1,206 mm
- Snow / year
- ≈1.1 m
- Midday UV at peak
- 7 (high)
- Sea at warmest
- 23°C / 73°F
- Population
- 19k
- Elevation
- 26 m
When is the best time to visit Islip?
For sunshine, the best time to visit Islip is July, then September and August. The dullest month is January (0/100, 81 mm of rain). The full month-by-month picture is in the table below.
How sunny is Islip?
Islip gets a moderate 2,252 hours of sunshine a year. 75 Sunshine Score points separate July (75) from January (0), so the month you pick matters. It ranks #302 of 580 destinations in United States for annual sunshine, below the national median of 2,279 hours. The year's 1,206 mm of rain spreads fairly evenly across the months, with no pronounced dry season.
Sunshine Score by month
| Month | Score | Day high | Night low | Rain | UV | Sea |
|---|---|---|---|---|---|---|
| January | 0 | 3° / 37°F | -3° / 27°F | 81 mm | 1 | 5° / 41°F |
| February | 0 | 3° / 37°F | -3° / 27°F | 85 mm | 2 | 4° / 39°F |
| March | 0 | 6° / 43°F | 0° / 32°F | 105 mm | 3 | 6° / 43°F |
| April | 24 | 12° / 54°F | 5° / 41°F | 106 mm | 5 | 9° / 48°F |
| May | 56 | 17° / 63°F | 11° / 52°F | 94 mm | 6 | 14° / 57°F |
| June | 72 | 23° / 73°F | 16° / 61°F | 110 mm | 7 | 19° / 66°F |
| July | 75 | 27° / 81°F | 20° / 68°F | 95 mm | 7 | 23° / 73°F |
| August | 73 | 27° / 81°F | 20° / 68°F | 103 mm | 7 | 23° / 73°F |
| September | 74 | 24° / 75°F | 17° / 63°F | 99 mm | 5 | 23° / 73°F |
| October | 52 | 17° / 63°F | 11° / 52°F | 120 mm | 3 | 18° / 64°F |
| November | 25 | 12° / 54°F | 6° / 43°F | 90 mm | 2 | 14° / 57°F |
| December | 0 | 6° / 43°F | 1° / 34°F | 118 mm | 1 | 8° / 46°F |
Sea temperature in Islip by month
The sea off Islip is warmest in July at around 23°C / 73°F, and coolest in February at 4°C / 39°F. The water sits at a comfortable 21°C or warmer roughly 3 months a year. Month-by-month sea-surface temperatures are in the Sea column of the table above.
See Islip on the interactive sunshine globe →
Nearby places for sunshine
- New Haven United States · 55 km · best in May · 2,191 h sun/yr
- White Plains United States · 59 km · best in May · 2,150 h sun/yr
- New York United States · 60 km · best in Sep · 2,252 h sun/yr
- Hartford United States · 132 km · best in May · 2,192 h sun/yr
- Trenton United States · 156 km · best in May · 2,166 h sun/yr
- Providence/Warwick United States · 174 km · best in Aug · 2,279 h sun/yr
Nearest destinations
- Teterboro United States · 81 km · 2,167 h sun/yr · best in May
- Montauk United States · 104 km · 2,278 h sun/yr · best in Jul
- Newburgh United States · 115 km · 2,022 h sun/yr · best in May
Head-to-head
How Islip compares month by month: Islip vs New York · Islip vs New Haven · Islip vs White Plains · all comparisons
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