Best time to visit Cardiff
Re-score for me — drag the dial — every chart on the page recolours live for your heat limit 27°C
Default 27 °C is the upper edge of the Holiday Climate Index "ideal comfort" band (Scott, Rutty, Amelung & Tang, 2016). Above this, most warm-tourism travellers report measurable discomfort.
How is this scored? HCI / Steadman / CCI gate — full methodology and citations below.
Compare with another destination
Add as many as you like — stacked below the main strips above. Each row is just the recent-window score strip and (for beach destinations) sea-temperature strip.
Tours in Cardiff
9 top-rated tours via Viator. Booking links earn this site a commission at no cost to you. Map locations are approximate (centred on Cardiff).
- 1
The Valleys tour or Swansea Bay tour. Please choose correctly. - 2
The Wandering Bard's Mythical West Wales Tour - 3
Cardiff Doctor Who Private Walking Tour - 4
Half Day Complete Cardiff Walking Tour - 5
A Silent Disco Adventure in Cardiff - 6
From Cardiff: 3 Amazing Castles, Tintern Abbey & Roman Caerleon - 7
From Cardiff: Guided South Wales' Amazing Waterfalls Tour - 8
From Cardiff: The Gower - Mumbles, Three Cliffs And Worms Head - 9
Private Tour: Doctor Who TV Locations and Tour of Cardiff
Last refreshed 2026-06-29.
Similar climatesLiverpool93% · Bristol93% · Haarlem92%
Other destinations with the most-alike year-round climate to Cardiff (apparent temperature, rain hours, sunshine — matched within the same trip-profile). The ±N chip compares each match's typical score for the current month against Cardiff's. Based on the 2020-2024 climatology, not this year's actual weather.
Month-by-month
| Month | Temp °C | Feels °C | Rain days | Rain h | Rain h/day | Humidity | Wind km/h | Sun h | UV | Interest | Score |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jan | 3–8 | 4 | 15 | 184 | 12.3 | 84% | 23 | 94 | — | Quiet | 4 |
| Feb | 4–10 | 6 | 16 | 225 | 14.1 | 81% | 28 | 102 | 1 | Quiet | 3 |
| Mar | 5–11 | 7 | 16 | 220 | 13.8 | 73% | 24 | 163 | 2 | Quiet | 4 |
| Apr | 5–13 | 10 | 11 | 151 | 13.7 | 65% | 21 | 225 | 3 | Quiet | 6 |
| May | 9–17 | 14 | 13 | 166 | 12.8 | 65% | 21 | 267 | 4 | Quiet | 6 |
| Jun | 12–20 | 18 | 12 | 152 | 12.7 | 64% | 20 | 279 | 5 | Quiet | 7 |
| Jul | 13–21 | 20 | 17 | 222 | 13.1 | 68% | 21 | 261 | 4 | Quiet | 6 |
| Aug | 14–21 | 20 | 16 | 193 | 12.1 | 69% | 21 | 237 | 4 | Peak | 6 |
| Sep | 12–19 | 18 | 12 | 168 | 14.0 | 72% | 20 | 193 | 3 | Busy | 7 |
| Oct | 10–15 | 13 | 21 | 252 | 12.0 | 78% | 22 | 147 | 2 | Moderate | 4 |
| Nov | 6–12 | 9 | 15 | 183 | 12.2 | 83% | 22 | 98 | 1 | Moderate | 4 |
| Dec | 5–9 | 6 | 18 | 222 | 12.3 | 86% | 25 | 74 | — | Quiet | 3 |
UV Index in Cardiff by Month
UV index in Cardiff peaks at 5 (moderate) in June, dropping to 0 (low) in January.
Best months in detail
June
7/1012–20°C (feels 18°C) · 12 rain days (152h) · 279 sun hours · 64% humidity · Quiet crowd · UV 5 (moderate) · sunniest 1 in 10 days reach 6 (high)
September
7/1012–19°C (feels 18°C) · 12 rain days (168h) · 193 sun hours · 72% humidity · Busy crowd · UV 3 (low) · sunniest 1 in 10 days reach 4 (moderate)
August
6/1014–21°C · 16 rain days (193h) · 237 sun hours · 69% humidity · Peak crowd · UV 4 (moderate)
Every month
Show the other 9 months in detail
January
4/103–8°C (feels 4°C) · 15 rain days (184h) · 94 sun hours · 84% humidity · Quiet crowd
February
3/104–10°C (feels 6°C) · 16 rain days (225h) · 102 sun hours · 81% humidity · Quiet crowd · UV 1 (low)
March
4/105–11°C (feels 7°C) · 16 rain days (220h) · 163 sun hours · 73% humidity · Quiet crowd · UV 2 (low)
April
6/105–13°C (feels 10°C) · 11 rain days (151h) · 225 sun hours · 65% humidity · Quiet crowd · UV 3 (low) · sunniest 1 in 10 days reach 4 (moderate)
May
6/109–17°C (feels 14°C) · 13 rain days (166h) · 267 sun hours · 65% humidity · Quiet crowd · UV 4 (moderate) · sunniest 1 in 10 days reach 6 (moderate)
July
6/1013–21°C (feels 20°C) · 17 rain days (222h) · 261 sun hours · 68% humidity · Quiet crowd · UV 4 (moderate) · sunniest 1 in 10 days reach 7 (high)
October
4/1010–15°C (feels 13°C) · 21 rain days (252h) · 147 sun hours · 78% humidity · Moderate crowd · UV 2 (low)
November
4/106–12°C (feels 9°C) · 15 rain days (183h) · 98 sun hours · 83% humidity · Moderate crowd · UV 1 (low)
December
3/105–9°C (feels 6°C) · 18 rain days (222h) · 74 sun hours · 86% humidity · Quiet crowd
Frequently asked questions about visiting Cardiff
When is the best time to visit Cardiff?
June is the highest-scoring month (7/10 on the Holiday Climate Index). Typical conditions: 12–20°C (12 rainy days). The top three months by score are June, September, August.
What is the worst time to visit Cardiff?
December is the lowest-scoring month (3/10). Typical conditions: 5–9°C (18 rainy days).
When are crowds lowest in Cardiff?
Search-interest seasonality (Google Trends 2021-2025) is lowest in March and peaks in August. Interest tracks both in-trip visitors and lead-time planners, so treat it as a "destination is on people's minds" signal rather than literal arrivals.
Which months in Cardiff have good weather but fewer tourists?
June (climate 7/10, crowd index 31) and April (climate 6/10, crowd index 7) — shoulder months with above-average climate and below-median search-interest. Often the best value-for-weather trade.
What is the UV index in Cardiff by month?
UV peaks at 5 (moderate) in June and is lowest in January at 0 (low). Monthly peak values: Jan —, Feb 1, Mar 2, Apr 3, May 4, Jun 5, Jul 4, Aug 4, Sep 3, Oct 2, Nov 1, Dec —.
What is the UV index in Cardiff in June?
June is the peak UV month in Cardiff, with a daily-peak UV index of 5 (moderate). Standard sun protection — sunglasses and light SPF — is recommended.
How high can UV get in Cardiff on the sunniest days?
Most days look like the monthly average, but on the sunniest ~1 in 10 days UV climbs higher than the mean suggests. July is the worst case: typical days average UV 4 (moderate), but the top 10% of days reach UV 7 (high) — and even higher. Months where the sunniest days routinely exceed the typical reading: April, May, June, July, September. Plan sun protection for the worst case, not the average.
Is air quality in Cardiff bad for travelers?
PM2.5 (fine-particle pollution) exceeds the WHO sensitive-group guideline (15 µg/m³) in 3 months: February, March, April. The worst month is March with a typical-day mean of 11 µg/m³ (moderate); on the worst 10% of days PM2.5 reaches 23 µg/m³ (unhealthy for sensitive) and higher. People with asthma, heart conditions, or sensitive children may want to avoid these months or limit outdoor activity. Source: CAMS via Open-Meteo.