Average daily temperatures in September
In September, the average daily high temperature in Wales sits around 64°F (18°C), while lows drop to a cooler 50°F (10°C), especially in the evenings. The weather in Wales in September can vary significantly depending on where you are, so it’s worth knowing what to expect by region.
In coastal areas such as Pembrokeshire and the Gower Peninsula, temperatures tend to be milder due to the sea, but breezes can create a chilly feeling. Expected highs are 62°F and 64°F (16°C and 18°C).
Inland, regions like the Brecon Beacons or Snowdonia can be chillier, especially at higher altitudes. Daytime highs hover around 59°F and 61°F (15°C and 16°C), but once the sun goes down, evenings can dip to a brisk 46°F (8°C) - perfect weather for outerwear and a hot drink by the fire.
Cities such as Cardiff or Swansea are slightly warmer, with more heat remaining in urban areas, with daytime highs expected at 63°F and 65°F (17°C and 18°C).
Wherever you are in Wales, September’s temperatures are mild enough for outdoor exploration but cool enough to remind you that fall is just around the corner.
What about the crowd and cost?
September in Wales is quieter than the summer peak, making it a great time to visit if you prefer fewer tourists. Popular spots like Snowdonia and Tenby are still active but far less crowded, especially midweek or later in the month. Accommodation prices start to dip as the high season winds down, and you might snag deals on hotels or B&Bs.
Attractions are easier to visit without the summer rush, and coastal trails and hiking routes become more relaxed. Overall, September is a balance of good weather, subdued crowds and more budget-friendly travel options.
Looking for more options for your vacation in September? Find the perfect vacation destination with our top suggestions.