Experience living here:
I’ve been in the Yuba City/Marysville area for over 20 years. While I don’t necessarily love the city specifically, I do love the location.
Weather:
If you’re familiar with the northern valley, than you’re familiar with our weather. We’re pretty much the same as Sacramento.
Here we’re typcially, or at least should be, hot in the summer and wet in the winter. Spring and fall can be pretty pleasant. More recently we’ve just been hot in the summer and cool but dry in the winter. This season has been a bit different and we’re getting lots of moisture. Temperatures can easily get over 100 in the summer and hover about freezing in the winter for the lows, but daytime winter highs are generally near 60.
Topography etc
Piper has it right. You’ll find acres and acres of walnuts, prunes, peaches, etc. Grassland? Not so much. Rice fields? Sure.
Pockets of more wild areas can be found squeezed between the farmlands and in the riparian areas. Several wildlife refuges are in the area and are great for birding and hunting. Pintail ducks and tundra swans seem to be the most numerous at the moment.
To the east are the Sierra Nevada foothills. If you’ve been to the foothills anywhere east of Redding or Fresno, then you’ll find these familiar too. Lots of scrubby oaks (love them) that turn to pine as you go higher. Grass Valley doesn’t see too much snow, nor does nearby Nevada City, but there is quite a bit up the road on highway 20 currently.