It’s free, requires no sign-up, and works globally.

Chrome: https://chromewebstore.google.com/detail/snow-days-calculator/hgjbkeohcgkmimgcnmkecikbmdakpndo

Edge: https://microsoftedge.microsoft.com/addons/detail/snow-days-calculator/lemdhaigpgajbfhljgjclkhiokakbpcl

Would love your feedback or feature ideas!