The best times to visit Letterkenny for ideal weather are
June 18th to September 9th
based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.
Letterkenny Travel Guide
Other Letterkenny Travel Info
Weather in Letterkenny
Average temperatures in Letterkenny vary somewhat. Considering humidity, temperatures feel cold for most of the year with a chance of rain or snow throughout most of the year. The area is less temperate than some — in the 14th percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Letterkenny, the hottest months are July, August, and then June. See average monthly temperatures below. The warmest time of year is generally late July where highs are regularly around 67.1°F (19.5°C) with temperatures rarely dropping below 50.8°F (10.4°C) at night.
Letterkenny Temperatures (Fahrenheit)
Letterkenny Temperatures (Celsius)
The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.
Letterkenny Perceived Temperature (F)
Letterkenny Perceived Temperature (C)
Average Letterkenny Temperatures by Month
Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.
|Month||Avg. High (°F)||Avg. Mean (°F)||Avg. Low (°F)|
|Month||Avg. High (°C)||Avg. Mean (°C)||Avg. Low (°C)|
Precipitation (Rain or Snow)
If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Letterkenny are April, September, and then June. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around mid April. For example, on the week of April 16th there is 1 day of precipitation on average. By contrast, it’s most likely to rain or snow in late December with an average of 4 days of significant precipitation the week of December 24th.
When can you find snow in Letterkenny? Weather stations report very large amounts of snow likely to be deepest around October, especially close to late October. The best time to ski (if at all) in Letterkenny is often around around October 22nd when fresh powder is deepest. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.
Chance of Precipitation
The graph below shows the % chance of rainy and snowy days in Letterkenny.
Snow on the Ground
The graph below shows the average snow on the ground in Letterkenny (in).
Average Rain and Snow by Month
|Month||Daily Chance of Rain||Average Snow Depth (in)||Total Precipitation (in)|
|Month||Daily Chance of Rain||Average Snow Depth (cm)||Total Precipitation (cm)|
Humidity and Wind
Letterkenny has some extremely humid months, and high humidity throughout the year. The least humid month is April (74.3% relative humidity), and the most humid month is November (89.6%).
Wind in Letterkenny is usually calm. The windiest month is January, followed by March and December. January’s average wind speed of around 8.3 knots (9.6 MPH or 15.4 KPH) is considered “a gentle breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early March where average top sustained speeds reach 16.4 knots, which is considered a moderate breeze.
Relative Humidity (%)
The graph below shows the average % humidity by month in Letterkenny.
The graph below shows wind speed (max and average) in knots.
Average Wind Speeds
Show Wind Speeds
All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.
|Month||Avg. Wind||Avg. Wind Feel||Sustained High Wind||High Wind Feel|
|Jan||8.3||Gentle breeze||14.8||Significant breeze|
|Feb||7.4||Gentle breeze||13.3||Significant breeze|
|Mar||8||Gentle breeze||14.2||Significant breeze|
|Apr||6.7||Light breeze||12.5||Significant breeze|
|May||7.4||Gentle breeze||13.1||Significant breeze|
|Jun||5.9||Light breeze||10.9||Gentle breeze|
|Jul||5.9||Light breeze||10.9||Significant breeze|
|Aug||6.2||Light breeze||11.4||Significant breeze|
|Sep||6.4||Light breeze||11.9||Significant breeze|
|Oct||6.4||Light breeze||12.3||Significant breeze|
|Nov||7||Gentle breeze||12.9||Significant breeze|
|Dec||7.6||Gentle breeze||14.3||Significant breeze|
Show Relative Humidity by Month
|Month||Avg. Relative Humidity|
Is it Safe to Travel to Letterkenny?
Our best data indicates this area is generally safe. As of Oct 07, 2019 there are no travel advisories or warnings for Ireland; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Oct 04, 2019.
The Busiest and Least Crowded Months
The busiest month for tourism in Letterkenny, Ireland is July, followed by January and August. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Letterkenny in April. Those willing to visit at these times will likely find it the least expensive month.
Estimated Tourism by Month
Most Popular Months to Visit
Overall Letterkenny Travel Experience by Season
Spring (March through May)
Humidity and temperatures combine to make this season feel moderately cold. Highs range from 64.4°F (18°C) and 48.3°F (9.1°C) with warmer temperatures in the later months. Rain is somewhat common with 8 to 10 days of significant precipitation per month. Spring is the slowest for tourism, which makes it a good time for those looking for deals.
Summer (June through August)
The middle-year months have comfortably cool weather with high temperatures that are comfortable. These months see moderate precipitation with 8 to 11 days of precipitation per month. June – August is the busiest season for tourism in Letterkenny, so lodging and other accommodations may cost more than usual.
Fall (September through November)
Fall daily highs range from 63.2°F (17.3°C) and 45.6°F (7.6°C), which will feel chilly given the humidity and wind. It rains or snows a good amount: 8 to 13 days per month. Tourism is fairly slow during these months due to the weather, so hotels may be lower priced.
Winter (December through February)
Weather is too cold this time of year in Letterkenny to be enjoyable for warm weather travelers. The average high during this season is between 48.3°F (9.1°C) and 43.9°F (6.6°C). On average, it rains or snows a very great amount: 12 to 16 times per month. These times of year are the second busiest with tourists.