USPS is increasing most of its prices on Sunday
1 oz letter up 3c to 63c
Additional oz stays the same at +24c per oz
1 oz letter = 63c
2 oz letter = 87c
3 oz letter = $1.11
3.5 oz letter (the max weight for a letter) = $1.35
Non-machineable surcharge up 1c to +40c. Non-machineable is a non-rectangular or non-flexible piece that won't bend as it goes through the sorting machines.
1 oz non-machineable letter = $1.03
2 oz non-machineable letter = $1.27
3 oz non-machineable letter = $1.51
3.5 oz non-machineable letter = $1.75
Domestic postcard up 4c to 48c
International mail 1oz letters and postcards up 5c to $1.45
You can purchase stamps at the current price until Saturday, however if you're buying online note that the USPS website will be down from 11pm eastern time (8pm pacific) for maintenance.
Most other categories of mail (large envelopes, packages, etc) are going up as well. Check online or at your post office.
These otters and flowers look happier in the snow than I will be later this weekend - stay safe if you're subject to a storm in the next few days.