While Mother's Day is today in the US, I know (from having lived in the UK) that Mother's Day isn't celebrated on the same day in all countries (when it is celebrated at all).
For a list of celebrations in various countries, one can always consult the Oracle of Wiki.
Anyway, it's kind of windy and chilly today in Ann Arbor, and most of the mothers that I've seen walking around with children, spouses and (sometimes) parents have broken out the winter clothes again. Indeed, there was one really cute little girl running around in pink ski pants, followed by beaming dad and mom, both also bundled up. Interestingly, temperatures in the mid-40s F (about 6-9C) would have been met with t-shirts and (possibly) shorts just a month or two months ago. It's amazing how quickly acclimation to weather changes how your body responds to dips in temperature.
Still, it's sunny, and although it reached below freezing last night, it is now in the low-50s F (low-10s C), there is enough solar gain to keep you warm despite the low-ish temperatures and stiff wind.