Best time to visit Llanberis
Month-by-month weather averages for Llanberis.
Llanberis, Wales, United Kingdom
°C
mm
- Average daily high and low
- Precipitation
- Good month
- Best month
- Made good or best by an event
| Month | Average daily high | Average daily low | Precipitation | Verdict |
|---|---|---|---|---|
| January | 7 °C / 45 °F | 3.9 °C / 39 °F | 158 mm / 6.2 in | neither best nor good |
| February | 7.2 °C / 45 °F | 3.9 °C / 39 °F | 122 mm / 4.8 in | neither best nor good |
| March | 8.4 °C / 47 °F | 4.2 °C / 40 °F | 109 mm / 4.3 in | neither best nor good |
| April | 10.8 °C / 51 °F | 5.8 °C / 42 °F | 75 mm / 2.9 in | neither best nor good |
| May | 13.3 °C / 56 °F | 8.5 °C / 47 °F | 92 mm / 3.6 in | neither best nor good |
| June | 15.7 °C / 60 °F | 11.2 °C / 52 °F | 98 mm / 3.9 in | good month |
| July | 17 °C / 63 °F | 12.9 °C / 55 °F | 117 mm / 4.6 in | good month |
| August | 16.7 °C / 62 °F | 13.1 °C / 56 °F | 128 mm / 5 in | neither best nor good |
| September | 15.7 °C / 60 °F | 11.7 °C / 53 °F | 136 mm / 5.3 in | neither best nor good |
| October | 13.1 °C / 56 °F | 9.7 °C / 49 °F | 164 mm / 6.5 in | neither best nor good |
| November | 10 °C / 50 °F | 6.8 °C / 44 °F | 175 mm / 6.9 in | neither best nor good |
| December | 8 °C / 46 °F | 5.1 °C / 41 °F | 197 mm / 7.7 in | neither best nor good |
Good and best months depend on more than temperature, rain and events. How they are chosen
Each activity on this page has its own good and best months, rated on twenty years of daily weather records. Which measures count, and how much, depends on the activity: humidity for exploring outdoors, wind for the beach, hiking and skiing, snow for skiing alone. Between them, the activities are rated on:
- Daytime highs
- Night-time lows
- How warm it feels
- Humidity
- How much of the day is sunny
- Hours of daylight
- Monthly rainfall
- How many days it rains
- Days of heavy rain
- Wind
- Snowfall and days with snow
- Major events, such as festivals
The chart shows the good and best months for exploring outdoors.
The event icon marks a month that an event lifts to good or best, such as a festival or a natural spectacle. Choose “Weather only” in the toolbar to rate the months on weather alone.
Best months by activity
Exploring outdoors
Mild days and nights, mostly dry and bright. The default for 'when should I go'.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: neither
- MMay: neither
- JJune: good
- JJuly: good
- AAugust: neither
- SSeptember: neither
- OOctober: neither
- NNovember: neither
- DDecember: neither
- Good
- June–July
Why these months
June · good
In its favour: share of daylight that is sunny 67%, feels like (high) 14.3 °C / 58 °F, average daily high 15.7 °C / 60 °F, precipitation 98 mm / 3.9 in, days with heavy rain 2.7 days, average daily low 11.2 °C / 52 °F.
Against: wet days 14.6 days, relative humidity 83%.
July · good
In its favour: feels like (high) 15.9 °C / 61 °F, share of daylight that is sunny 65%, average daily high 17 °C / 63 °F, precipitation 117 mm / 4.6 in, average daily low 12.9 °C / 55 °F, days with heavy rain 4 days.
Against: wet days 17.4 days, relative humidity 84%.
Hiking and trekking
Cool enough to climb in, dry enough to enjoy, long enough days.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: best
- MMay: best
- JJune: best
- JJuly: good
- AAugust: good
- SSeptember: good
- OOctober: neither
- NNovember: neither
- DDecember: neither
- Best
- April–June
- Good
- July–September
Why these months
April · best
In its favour: average daily high 10.8 °C / 51 °F, precipitation 75 mm / 2.9 in, days with heavy rain 2.2 days, average daily low 5.8 °C / 42 °F, share of daylight that is sunny 70%, daylight per day 14 h, feels like (high) 7.5 °C / 46 °F, wind (daily max) 23 km/h / 14 mph.
Against: wet days 13.3 days.
May · best
In its favour: average daily high 13.3 °C / 56 °F, precipitation 92 mm / 3.6 in, average daily low 8.5 °C / 47 °F, days with heavy rain 2.5 days, share of daylight that is sunny 69%, daylight per day 15.9 h, feels like (high) 10.9 °C / 52 °F, wind (daily max) 23 km/h / 14 mph.
Against: wet days 14.9 days.
June · best
In its favour: average daily high 15.7 °C / 60 °F, precipitation 98 mm / 3.9 in, feels like (high) 14.3 °C / 58 °F, average daily low 11.2 °C / 52 °F, share of daylight that is sunny 67%, daylight per day 16.9 h, days with heavy rain 2.7 days, wind (daily max) 22 km/h / 13 mph.
Against: wet days 14.6 days.
July · good
In its favour: average daily high 17 °C / 63 °F, precipitation 117 mm / 4.6 in, feels like (high) 15.9 °C / 61 °F, average daily low 12.9 °C / 55 °F, share of daylight that is sunny 65%, daylight per day 16.4 h, wind (daily max) 22 km/h / 14 mph.
Against: wet days 17.4 days, days with heavy rain 4 days.
August · good
In its favour: average daily high 16.7 °C / 62 °F, feels like (high) 15.2 °C / 59 °F, average daily low 13.1 °C / 56 °F, share of daylight that is sunny 64%, daylight per day 14.7 h, precipitation 128 mm / 5 in, days with heavy rain 4 days, wind (daily max) 24 km/h / 15 mph.
Against: wet days 19.4 days.
September · good
In its favour: average daily high 15.7 °C / 60 °F, feels like (high) 13.7 °C / 57 °F, average daily low 11.7 °C / 53 °F, share of daylight that is sunny 62%, daylight per day 12.7 h, precipitation 136 mm / 5.3 in, wind (daily max) 25 km/h / 15 mph.
Against: wet days 16.4 days, days with heavy rain 4.5 days.
An activity is listed only where it applies: skiing at ski destinations, beach and swimming at beach destinations. The nearest ski area is Glencoe Mountain Resort, 391 km away.
Weather averages
Monthly averages over twenty years, 2006–2025. Highs, lows and precipitation are in the chart at the top.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels like (high) | 2.7 °C | 2.8 °C | 4.3 °C | 7.5 °C | 10.9 °C | 14.3 °C | 15.9 °C | 15.2 °C | 13.7 °C | 10.2 °C | 6.3 °C | 3.8 °C |
| Days with heavy rain | 6.2 days | 4.2 days | 3.3 days | 2.2 days | 2.5 days | 2.7 days | 4 days | 4 days | 4.5 days | 5.7 days | 6 days | 7 days |
| Time rain usually falls | 3 am | 5 am | 1 am | 11 am | 4 pm | 3 pm | 2 pm | 12 pm | 12 pm | 8 am | 10 pm | 8 pm |
| Sunshine per day | 3.8 h | 5.4 h | 7.5 h | 9.8 h | 11 h | 11.4 h | 10.6 h | 9.5 h | 7.9 h | 5.7 h | 4.1 h | 3.2 h |
| Relative humidity | 86% | 85% | 83% | 80% | 81% | 83% | 84% | 85% | 84% | 85% | 85% | 86% |
Air quality
Averaged over a shorter period (2022–2025) than the twenty-year averages above, and not counted towards good or best months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air pollution (PM2.5) 2022–2025 | 4.9 µg/m³ | 4.9 µg/m³ | 6.8 µg/m³ | 7.7 µg/m³ | 8.3 µg/m³ | 8.3 µg/m³ | 6.1 µg/m³ | 6.7 µg/m³ | 6.3 µg/m³ | 5.1 µg/m³ | 4.3 µg/m³ | 4.3 µg/m³ |
| Air pollution (PM2.5, daily peak) 2022–2025 | 7.9 µg/m³ | 8.1 µg/m³ | 10.8 µg/m³ | 12.1 µg/m³ | 13.4 µg/m³ | 13.2 µg/m³ | 9.5 µg/m³ | 10.1 µg/m³ | 9.5 µg/m³ | 7.6 µg/m³ | 6.9 µg/m³ | 6.9 µg/m³ |
- Good 15 µg/m³ or less
- Fair 15 to 25 µg/m³
- Moderate 25 to 37.5 µg/m³
- Poor 37.5 to 50 µg/m³
- Very poor 50 to 75 µg/m³
- Extremely poor over 75 µg/m³
Each figure is compared with the World Health Organization's guideline for a day's air, 15 µg/m³ or less, and with its interim targets above that. The words are ours: the WHO does not name its steps. The figures are modelled monthly averages, so single days can be well above them. The daily peak is the average of each day's highest hour, shaded on the same scale.
World Heritage sites nearby
UNESCO World Heritage sites within 25 km, nearest first.
- The Slate Landscape of Northwest Wales
1 km away
- Castles and Town Walls of King Edward in Gwynedd
10 km away