When is it safe to plant in Lethbridge, and when should you expect the first fall frost? Slide to a date to see the typical frost risk.
These are averages from Environment Canada climate normals (1981–2010) for the Lethbridge research station, as published by The Old Farmer's Almanac, using a roughly one-in-three chance of frost on each date. Any given year can be earlier or later, and low spots, river valleys and open fields often frost first.
Early May (hardy): peas, spinach, lettuce, radishes, onions, potatoes and carrots handle a light frost.
Late May to early June (tender): tomatoes, peppers, beans, cucumbers, squash, corn and bedding annuals. Wait until frost risk is low and the soil has warmed.
Short season tip: with only about 3½ months between frosts, pick early-maturing varieties and start tomatoes and peppers indoors.