Summer approaching?

Now that May is almost at an end, people have been asking me about planting schedules and whether or not it is safe to plant their flower and vegetable gardens yet. The crazy weather of the last week, makes me doubt that its warm enough for most annuals to be showing their heads outside at nighttime, but as a general rule of thumb, if your seeds are still underground( ie, no green shoots showing) they should survive the light frosty nights of Thunder Bay. (We cover up green shoots if there is a risk of frost in the city)
It does seem a little strange to a European, that we would be getting frost warnings at the end of May, but this is the north shore of Lake Superior, so I guess all is forgiven. I do remember though when we first came to live in this beautiful part of Canada, local people thought us strange that we would be planting out our vegetable garden before the magic date of May 23rd. This date seems to be enshrined in local lore as the start date to all gardening and summer activities( given the frost warnings of the last few days, this seems a little off for summer to be beginning!) I think we disproved this theory within the first year of planting as our fall crops were magnificent that year.
Walking around our neighbourhood, I have seen gardens full of pea shoots sprouting and lettuce. The leaves are finally on the trees( thanks to the magic May 23rd date, when they usually reappear) and Summer activities do seem to be starting.

Happy Planting Everyone!