Jacob H.
Yelp
The downtown farmer's market in St. Paul is always a joy to visit. It is nice having a layout with the roof over the walkway, and parking (I use the Union Depot ramp off Kellogg) is close by. If you are lucky enough to take a bus or light rail, those are just a block away, perhaps 2 if you walk from the bus.
The selection of vendors is good, even in the winter when the market goes indoors. There are frozen items, jarred sauces and salsa, quilts and cheeses, meats of all sorts, and plants and vegetables.
It is still largely a cash operation, so you may want to visit your favorite ATM before you visit. Also, bring your own bags if you like.
If you want to avoid being hungry before buying stuff, there are some ready-to-eat options there, which you could visit first. A hot-dog and bratwurst cart is always on the southeast corner, with very tasty wares.
Keep in mind that the produce is seasonal. While the weather may be nice enough to visit, it may not have been nice enough for long enough for crops to have grown to the point of harvest.
It is also a good idea to walk the whole market first, noting the prices of various items, because you will then know if you are getting the best price for the quality you want. There can be a many-dollar range for the same amount of some produce from different vendors, but quality or individual size of the produce may be the deciding factor.