It has been cold lately, but starting today the low will not drop under 50 (on the 10 day forecast). I might start planting my annuals this week.
I don't have any experience with Dahlias, so I'm not sure about those.
What kind do you have?

I would wait until the soil is warmer. For things like Dahlias, it isn't necessarily the air temperature that is most important, it's the soil temp. I have them sprouting inside, but the temp there is 68. They did not begin to sprout until the temps reached about 65 or so. I'd wait 2 weeks until the ground warms up consistantly.

GGG

What kind?...When I planted the bulbs in the pots, I cut out the flowers' picture and taped them to the pot...so I would know which color to place where in the garden....some are suppose to to grow to 32 inches high (my red ones)...and the others, 35 inches high...I just buy what looks pretty to me...one picture reads: Firebird...another reads, Haley Jane...another reads, Bicolor Decorative Dahlia, and another, Dahlia Grandes Decoratives....and some names were cut out...I thought Dahlias might look good mixed in with Roses (?)...Know any thing that looks good and will keep them from collapsing on the ground?
I'm calling this my experimental year with Dahlias and Roses.

i have had dahlias for about three years now. I planted them in April and they have been in the ground ever since! The multiply and come back each year. Was I supposed to dig them up each year?

I too leave my tuberos Dahlias in the ground year round, for the last 3-4 years. They are spouting at the moment and about 5 inches high.

I'm experimenting with Dahlias this year too...and don't tempt me on the roses...I'm seriously contemplating it. :)

I've been doing some research on the different types of Dahlias and I've decided that I want one Dinnerplate (12" blooms) and two Ball Dahlias. I'm going to the Dahlia Society tuber sale on Monday to buy some.

I normally leave Dahlia in the ground all winter too. Mulched well, I've never had a problem. This year I decided to divide them so I dug them up and took them inside.

I have had problems before planting tubers that were kept in warm soil and then suddenly planting them in cooler soil. The tops died off and I was back to square one, waiting a few weeks to re-sprout. Ended up 2 weeks behind.

GGG

I just attended a discussion given by the Dahlia Society. The recommendation is to NOT dig Dahlias for storage, but to mulch for the winter, then AFTER they've sprouted in the garden, carefully dig and divide them, be certain to always keep a growing bud or sprout on the newly divided tuber, a section of the base of the previous year's stem. You can replant them immediately, or share the extras around.

And a note... If a tuber breaks off and it doesn't have a bud or sprout, it will NEVER sprout.

Another tip is to put a stake in the hole when you plant the new or newly divided tuber, that way you won't skewer the tuber.

I grew Dahlias for years in California, and though it is admittedly a milder climate, culture is the same.

i suspect we used to have to dig dahlias here when we were still a zone 7. now we appear to be a zone 8.