Blog / Rain Odds by Month
The chance of rain on your Long Island event date, month by month
The chance of rain on Long Island changes less across the year than most hosts expect, and the months people fear most are not the wettest ones. Thirty years of daily records from the Islip weather station show how many days each month actually get wet, and what that means for the date you are holding.
Pick your month
Days with measurable rain at Islip, every month of the year
Each bar is the average number of days in that month with at least a hundredth of an inch of rain, from the official 1991 to 2020 climate normals for Long Island MacArthur Airport. Tap a month to see how often it rains and how often it pours. A wet month is rarely a reason to give up the date; it is a reason to plan wedding tent rentals and party tents with sidewalls ready to drop.
Source: NOAA National Centers for Environmental Information, Summary of Monthly Normals 1991 to 2020, Islip station USW00004781. The wet share is the average count of wet days divided by the days in the month.
Reading the numbers
A wet day is any day with a hundredth of an inch
The National Weather Service defines measurable precipitation as 0.01 inch or more, and the same line is used when your forecast says 30 percent chance of rain. That is a very low bar. A ten minute shower at four in the morning counts. So does a mist that never wets the lawn.
That is why the second number matters more for a party. Days with half an inch or more are the ones that soak a lawn, fill a low corner of the yard and send guests under cover for real. At Islip every month averages between 2.2 and 3.3 of them, winter or summer. December has the most. May and July have the fewest.
Put the two numbers side by side and a pattern shows up. Late summer and fall get wet on fewer days, but August still averages 4.24 inches, more than April. The rain comes in fewer, heavier bursts. Spring is the reverse: more wet days, many of them light and gray.
What a tent plan answers
A roof handles light rain on its own. Heavier rain is a question of walls, ground and walkways. Sidewalls on the windward side, flooring where the lawn sits low and a covered path to the bar are the tent accessories that decide whether a wet evening feels like a problem or like weather.
Month by month
What each month means for an outdoor event
The event season from April through October, with the normals in figures and a plain reading of what they ask of the plan.
| Month | Wet days | Days with 0.5 in or more | Normal total | Planning reading |
|---|---|---|---|---|
| April | 11.3 | 2.5 | 4.06 in | Frequent light rain and soft ground. Plan walls and flooring as part of the tent, not as a backup. |
| May | 11.6 | 2.2 | 3.28 in | The most wet days of the season, but the fewest soakers. Showers pass. A tent carries the day easily. |
| June | 10.1 | 2.4 | 4.00 in | Odds start to fall. Afternoon storms are the risk, so keep sidewalls on site even for an open tent. |
| July | 9.1 | 2.2 | 3.26 in | Among the driest months. Rain tends to be short and hard. Heat is often the bigger planning question. |
| August | 8.9 | 2.4 | 4.24 in | Few wet days, heavy totals. When it rains it means it, so drainage and a covered walkway matter. |
| September | 8.6 | 2.6 | 3.60 in | The fewest wet days of any month. Peak hurricane season too, so watch the tropics the week of the event. |
| October | 9.2 | 2.6 | 3.97 in | Still dry by count, with the most one-inch days of the season. Cold evenings join rain as the reason to close the tent. |
For a wedding, the lesson is that no month on Long Island is dry enough to skip the rain plan, and none is wet enough to rule out. A wedding tent sized for everyone to sit, eat and dance under one roof is the plan that works in all seven months. If you want the sky in the photographs either way, a clear top tent keeps the view on a dry night and keeps everyone dry on a wet one. September hosts should also read our note on hurricane season and outdoor events.
From Google reviews
Hosts who planned for the weather and got the day they wanted
"We rented our tent from TGIF for our backyard wedding, and it was one of the best decisions we made. We weren't sure a tent would work around our pool, but Mike reassured us that his team could make it happen. He was quick to answer every question, and the setup team was prompt and professional. Highly recommend!"
"TGIF handled my event in Suffolk County, and they absolutely exceeded my expectations. The setup was perfect, the event went beautifully, and the team did an excellent job."
Straight answers
Rain and event date questions
Hold the date, plan the roof
Tell us the date and we will plan it for the wet version
Our family has been putting up tents on Long Island since 1975, and the fleet has grown from two tents to more than 500. Send us the date and the property and we will build the plan around the day it might rain.