I checked out the spots from splocs.com for SD area - Can any confirm that the two flat water spots are accurate (Sail Bay & Enchanted Cove)? How about the waves spot (Turmo)? Any other spots that are good but not noted on splocs?
Secondly - when is the best time to visit for winds? Im reading April/May... how about late March?
I live in SD and I can't pinpoint a season. People say the spring is better, but to me it seems like year round low teens with a jolt of exciting wind every now and then.
Your best bet is a big kite and a big board or foil board. With that setup, many of the days are doable. Without it, hopefully you get lucky and catch an infrequent day when it blows consistently above 15 mph. Foil kites and foil boards have really opened up a lot of days and made SD a viable place to live and kite, although a pretty specific style of kiting.
Another wave spot is Silver Strand State Beach, sometimes it has stronger wind than Tourmo, other times its vice versa. The beach is less crowded and bigger, it can be pretty big at low tide. It's $10 to park for the day or else walk from the neighborhood across the highway.
Down the beach from Tourmo you can also go to Pacific Beach/Mission Beach which is a little more spread out than Tourmo. Really I have seen kites along that whole beach at one time or another. But I think they are more common by the parking spots at PB Blvd and by the roller coaster. Sail Bay is just on the other side of the peninsula from that beach. Sail Bay has sort of been a go-to spot this fall and winter for the light wind foil crowd. On the weekends though it hosts regattas and what seems like a billion SUP's so it can be a nail biter. Enchanted Cove, well, sometimes it's good, sometimes it's awesome, lots of times the wind isn't making it in that far. When the wind is solid it's a pretty fun flatwater spot, but it can be crowded too.
Then there's J street in Chula Vista, a pretty small launch area with some hazards, but the wind seems to blow decently compared to elsewhere and if it's consistent enough and you're confident you can go downwind behind a skinny island and the water is BUTTER. You just need to get back upwind to the beach. Otherwise you're drifting into rip rap, or the marsh or the pier or the marina.