Salerno works well across a longer season than most of the Amalfi Coast. Spring (April to June) is the best time: warm enough for the lungomare, the Amalfi ferry services running fully, and the crowds still manageable. September and October are similarly good — the summer peak has passed but the sea is still warm.
July and August bring heat and more visitors as people use Salerno as an Amalfi base. The city is less overwhelmed than Positano or Ravello, but accommodation prices rise. The Luci d'Artista winter light installation (November to February) is worth knowing about if you visit off-season — the city centre and lungomare are decorated with large-scale light art.