A lovely start to the week, plenty of sunshine around but feeling rather cold. The northerly flow of the wind isn't helping much either, but get out of the breeze and the sunshine will feel pleasant. Highs today of just 5-6C and almost cloudless skies.
Overnight the breeze becomes very light and variable, with the clear skies remaining. That combination will allow temperatures to fall away to -3C, but possibly lower. So a widespread air frost and the risk of seeing some freezing fog patches developing too.
Tuesday starts icy cold across Wales but on the whole cloudless and sunny. Any fog patches that develop overnight could be slow to shift. It will be colder than today with highs of just 3-4C. However, if you're stuck in a foggy area, temperatures here could be even colder.