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Weather & Climate in Porthmadog, United Kingdom
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Porthmadog experiences four distinct seasons with an average annual temperature of 49°F (9°C). Winters average 40°F in January while summers reach 59°F in July / relatively mild seasonal variation. The area gets 249 sunny days per year, above the national average. Annual precipitation totals 47.9 inches (wetter than the 38-inch national average). The city sits at an elevation of 13 feet.
Temperature
40°F Jan (4°C)
59°F Jul (15°C)
| Annual Average | 48.8°F |
| 10% below US avg | |
| January Average | 40°F (4°C) |
| July Average | 59°F (15°C) |
| Sunny Days | 249 days/yr |
Geography
| Elevation | 13 ft (4 m) |
| Area | 6.2 sq mi (16.0 km²) |
| Population Density | 482/sq mi |
| Coordinates | 52.9292°N, 4.1314°W |
| Timezone | Europe/London |
Precipitation & Snow
Air Quality
Earthquake History
39 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.8.
| Sep 22, 2002 | 2 km ESE of Wombourn, United Kingdom | M4.8 | 141 km | 9 km |
| Apr 2, 1990 | 4 km NNE of Presteigne, United Kingdom | M4.7 | 103 km | 18 km |
| Oct 25, 1999 | 10 km N of Hirwaun, United Kingdom | M4.5 | 128 km | 10 km |
| Feb 17, 2018 | 5 km NE of Clydach, United Kingdom | M4.3 | 135 km | 12 km |
| Oct 21, 2002 | 1 km ESE of Manchester, United Kingdom | M4.3 | 141 km | 5 km |
| May 29, 2013 | 14 km WSW of Nefyn, United Kingdom | M3.8 | 40 km | 10 km |
| Oct 24, 2002 | 2 km WNW of Droylsden, United Kingdom | M3.8 | 144 km | 4 km |
| Mar 7, 1996 | 3 km SW of Clive, United Kingdom | M3.8 | 93 km | 10 km |
| Feb 14, 2005 | 2 km SW of Conwy, United Kingdom | M3.8 | 42 km | 5 km |
| May 30, 2022 | 2 km ESE of Prees, United Kingdom | M3.6 | 101 km | 10 km |
| Oct 22, 2002 | 0 km S of Droylsden, United Kingdom | M3.5 | 145 km | 4 km |
| Feb 12, 2002 | 1 km SSE of Deri, United Kingdom | M3.5 | 149 km | 8 km |
| Mar 17, 1994 | 5 km WNW of Newtown, United Kingdom | M3.5 | 68 km | 10 km |
| Jul 29, 1992 | 8 km WNW of Caernarfon, United Kingdom | M3.5 | 31 km | 10 km |
| Feb 24, 2023 | 1 km ENE of Brynmawr, United Kingdom | M3.4 | 141 km | 10 km |
| Jun 16, 1991 | 11 km WSW of Knighton, United Kingdom | M3.3 | 93 km | 10 km |
| Sep 1, 1999 | 4 km SSW of Llanfairfechan, United Kingdom | M3.3 | 33 km | 10 km |
| Feb 10, 1994 | 2 km NNE of Tregarth, United Kingdom | M3.3 | 32 km | 10 km |
| Feb 20, 1995 | England, United Kingdom | M3.3 | 135 km | 5 km |
| Oct 23, 2002 | 0 km WSW of Droylsden, United Kingdom | M3.3 | 145 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 40°F (4°C) | 4.7 in | Coldest |
| February | 40°F (5°C) | 3.5 in | |
| March | 43°F (6°C) | 4.2 in | |
| April | 46°F (8°C) | 2.9 in | |
| May | 51°F (11°C) | 2.7 in | Driest |
| June | 56°F (13°C) | 3.0 in | |
| July | 59°F (15°C) | 3.2 in | Warmest |
| August | 59°F (15°C) | 3.8 in | |
| September | 55°F (13°C) | 4.2 in | |
| October | 51°F (10°C) | 5.0 in | |
| November | 45°F (7°C) | 5.5 in | Wettest |
| December | 42°F (5°C) | 5.2 in |
Porthmadog has a seasonal temperature swing of 19°F / from 40°F in January to 59°F in July. Total annual precipitation is 47.9 inches, with November being the wettest month (5.5") and May the driest (2.7").