This month for peas, which unlike chard are of course not a cole crop. Season here is long and mild, but not hot. Rainfall bottoms out in July, liberal irrigation of plants (such as annual vegetables) requiring moist soil is necessary for good results, even survival.

See publicatons of Sunset Publishing, Seattle Tilth, Timber Press and King County Cooperative Extension Service for more about vegetable gardening here.

I'll second the recommendation on the Seattle Tilth publication for when to plant what. I don't remember its name but many larger nurseries and bookstores carry it and you could prob. get it via their website.
Frosts here are approx. April 1 for last frost and 10/30 for first one. That doesn't matter a heckuva lot though because you still shouldn't plant any warm weather stuff til May or so. Night temps and soil are still too cool until then. Peas can go in between 2/15 up til May. Earlier is better, esp. if you plant older, less disease-tolerant varieties.
BTW, cole crops refers only to plants like cabbage, brocc., cauliflower, kale and other tasties.