These days Chiffchaff are present and calling locally all year. No cowslips to speak of near by but the Blackthorn is on the verge of flowering so spring is on it's way.... you hear the first singing Chiffchaff and see the first Cowslips.
Spring starts a bit later here than down south (I think I read somewhere that there's something like a two week delay between key spring events in the south and in the far north of the country).
But for me it's seeing the first flowering daffodils (yesterday for me).