The best times to visit Merthyr Tydfil for ideal weather are
June 25th to August 26th
based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.
Merthyr Tydfil Travel Guide
Other Merthyr Tydfil Travel Info
Weather in Merthyr Tydfil
Temperature
Average temperatures in Merthyr Tydfil 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 12th 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 Merthyr Tydfil, 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 66.8°F (19.3°C) with temperatures rarely dropping below 49.9°F (9.9°C) at night.
Merthyr Tydfil Temperatures (Fahrenheit)
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Merthyr Tydfil Temperatures (Celsius)
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“Feels-Like” Temperatures
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.
Merthyr Tydfil Perceived Temperature (F)
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Merthyr Tydfil Perceived Temperature (C)
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Average Merthyr Tydfil 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.
Show Fahrenheit
| Month | Avg. High (°F) | Avg. Mean (°F) | Avg. Low (°F) |
|---|---|---|---|
| Jan | 42.3 | 37.9 | 32.6 |
| Feb | 43.4 | 38.1 | 32.7 |
| Mar | 48.2 | 40.5 | 33.2 |
| Apr | 54.5 | 45.4 | 36.4 |
| May | 57.9 | 49.7 | 41.7 |
| Jun | 63 | 54.6 | 45.8 |
| Jul | 64.9 | 57.1 | 49.3 |
| Aug | 64 | 56.3 | 48.7 |
| Sep | 61 | 53.1 | 45.1 |
| Oct | 55.4 | 49.2 | 42.7 |
| Nov | 48.3 | 43.2 | 37.5 |
| Dec | 43.4 | 38.7 | 33.2 |
Show Celsius
| Month | Avg. High (°C) | Avg. Mean (°C) | Avg. Low (°C) |
|---|---|---|---|
| Jan | 5.7 | 3.3 | 0.3 |
| Feb | 6.3 | 3.4 | 0.4 |
| Mar | 9 | 4.7 | 0.7 |
| Apr | 12.5 | 7.4 | 2.4 |
| May | 14.4 | 9.8 | 5.4 |
| Jun | 17.2 | 12.6 | 7.7 |
| Jul | 18.3 | 13.9 | 9.6 |
| Aug | 17.8 | 13.5 | 9.3 |
| Sep | 16.1 | 11.7 | 7.3 |
| Oct | 13 | 9.6 | 5.9 |
| Nov | 9.1 | 6.2 | 3.1 |
| Dec | 6.3 | 3.7 | 0.7 |
Precipitation (Rain or Snow)
If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Merthyr Tydfil are April, March, 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 late May. For example, on the week of May 21st there is 1 day of precipitation on average. By contrast, it’s most likely to rain or snow in early to mid January with an average of 4 days of significant precipitation the week of January 8th.
When can you find snow in Merthyr Tydfil? 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 Merthyr Tydfil is often around around December 17th 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 Merthyr Tydfil.
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Snow on the Ground
The graph below shows the average snow on the ground in Merthyr Tydfil (in).
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Average Rain and Snow by Month
Show Inches
| Month | Daily Chance of Rain | Average Snow Depth (in) | Total Precipitation (in) |
|---|---|---|---|
| Jan | 48% | 5.7 | 6.8 |
| Feb | 38% | 2.1 | 3.8 |
| Mar | 28% | 1.3 | 3.5 |
| Apr | 25% | 0.8 | 2.8 |
| May | 33% | 0.8 | 3.9 |
| Jun | 28% | 0 | 3.3 |
| Jul | 37% | 0 | 5 |
| Aug | 37% | 0 | 4.5 |
| Sep | 29% | 0 | 3.7 |
| Oct | 41% | 23.6 | 5.2 |
| Nov | 52% | 5.4 | 6.9 |
| Dec | 50% | 2.2 | 7.9 |
Show Centimeters
| Month | Daily Chance of Rain | Average Snow Depth (cm) | Total Precipitation (cm) |
|---|---|---|---|
| Jan | 48 | 14.5 | 17.3 |
| Feb | 38 | 5.3 | 9.7 |
| Mar | 28 | 3.3 | 8.9 |
| Apr | 25 | 2 | 7.1 |
| May | 33 | 2 | 9.9 |
| Jun | 28 | 0 | 8.4 |
| Jul | 37 | 0 | 12.7 |
| Aug | 37 | 0 | 11.4 |
| Sep | 29 | 0 | 9.4 |
| Oct | 41 | 59.9 | 13.2 |
| Nov | 52 | 13.7 | 17.5 |
| Dec | 50 | 5.6 | 20.1 |
Humidity and Wind
Merthyr Tydfil has some extremely humid months, and high humidity throughout the year. The least humid month is April (76.3% relative humidity), and the most humid month is January (91.1%).
Wind in Merthyr Tydfil is usually calm. The windiest month is January, followed by December and February. January’s average wind speed of around 8.5 knots (9.8 MPH or 15.8 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 late December where average top sustained speeds reach 17.5 knots, which is considered a fresh breeze.
Relative Humidity (%)
The graph below shows the average % humidity by month in Merthyr Tydfil.
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Wind
The graph below shows wind speed (max and average) in knots.
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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 | 8.5 | Gentle breeze | 15.1 | Significant breeze |
| Feb | 7.4 | Gentle breeze | 13.2 | Significant breeze |
| Mar | 6.6 | Light breeze | 12.4 | Significant breeze |
| Apr | 6.6 | Light breeze | 11.9 | Significant breeze |
| May | 6.8 | Light breeze | 12.1 | Significant breeze |
| Jun | 6 | Light breeze | 10.9 | Gentle breeze |
| Jul | 6.1 | Light breeze | 11 | Significant breeze |
| Aug | 6.2 | Light breeze | 11.1 | Significant breeze |
| Sep | 5.5 | Light breeze | 10.4 | Significant breeze |
| Oct | 7.1 | Gentle breeze | 12.5 | Significant breeze |
| Nov | 7.2 | Gentle breeze | 13 | Significant breeze |
| Dec | 8.2 | Gentle breeze | 14.8 | Significant breeze |
Show Relative Humidity by Month
| Month | Avg. Relative Humidity |
|---|---|
| Jan | 91.1% |
| Feb | 88.6% |
| Mar | 82.2% |
| Apr | 76.3% |
| May | 76.7% |
| Jun | 77.4% |
| Jul | 80.7% |
| Aug | 83.5% |
| Sep | 84.1% |
| Oct | 87.6% |
| Nov | 90.6% |
| Dec | 90.9% |
Is it Safe to Travel to Merthyr Tydfil?
Our best data indicates this area is somewhat safe. As of Dec 04, 2023 there are travel warnings for the United Kingdom; exercise a high degree of caution. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Nov 27, 2023.
The Busiest and Least Crowded Months
The busiest month for tourism in Merthyr Tydfil, the United Kingdom is September, followed by August and October. 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 Merthyr Tydfil in December. Those willing to visit at these times will likely find it the least expensive month.
Estimated Tourism by Month
Most Popular Months to Visit
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Overall Merthyr Tydfil Travel Experience by Season
Spring (March through May)
Humidity and temperatures combine to make this season feel moderately cold. Highs range from 61.5°F (16.4°C) and 45.5°F (7.5°C) with warmer temperatures in the later months. Rain is somewhat common with 7 to 10 days of significant precipitation per month. Spring is fairly slow 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 brisk. These months see moderate precipitation with 9 to 11 days of precipitation per month. June – August is the second busiest season for tourism in Merthyr Tydfil, so lodging and other accommodations may cost slightly more.
Fall (September through November)
Fall daily highs range from 63.1°F (17.3°C) and 44°F (6.7°C), which will feel chilly given the humidity and wind. It rains or snows a good amount: 9 to 16 days per month. Tourism is the busiest during these months due to the weather, so hotels may be higher priced.
Winter (December through February)
Weather is too cold this time of year in Merthyr Tydfil to be enjoyable for warm weather travelers. The average high during this season is between 45.5°F (7.5°C) and 40.1°F (4.5°C). On average, it rains or snows a very great amount: 11 to 15 times per month. These times of year are the slowest with tourists.
Best Times to Travel› the United Kingdom › Merthyr Tydfil, the United Kingdom