| Variable | Least Change (2050s) | Hot/Dry (2050s) | Hot/Wet (2050s) |
| Temperature |
+ 2ºC (~4ºF)1 the greatest warming is expected to occur during the cold-season Extremes: less than 5 additional days per year with temperatures >= 95ºF2 15 less days per year with temperatures <= 32°F3 |
+ 4ºC (~7ºF) the greatest warming is expected to occur during the cold-season |
less than + 4ºC (~7ºF) the greatest warming is expected to occur during the cold-season |
| Precipitation |
5% increase4 Future snowfall amounts are less certain.5 We do know that snow pack is forming later and melting earlier. Extremes: Intensity of extreme precipitation events will likely continue to increase, and severe drought is becoming less common. |
5% increase |
+ 15% overall (25% increase in wintertime total precipitation but the number of days6 that receive snowfall are expected to decrease by 25%) up to +30% increase in number of days with > 1 inch liquid water equivalent |
| Frost Free Period |
+20 frost-free days in growing season7 Last spring freeze 1 week earlier |
||
| Wind | no change | no change | no change |
| Lake Levels | no change | - 0.6 m | + 0.4 m |
| Lake Superior Water Temperature | +2ºC (3.6ºF) in warm-season8 | ||
| Lake Superior Ice Cover | -12 days with ice cover9 | up to -47 days with ice cover | up to -47 days with ice cover |
- 1. annual mean: 4.1ºC (39.4ºF); DJF mean: -8.2ºC (17.3ºF); JJA mean: 14.9ºC (58.8ºF)
- 2. heat waves are not expected to increase in the northern Midwest
- 3. there will be less cold events during the cold-season
- 4. annual mean: 24.6 inches; DJF mean: 0.69 inches; JJA mean: 3.3 inches; Precipitation totals include rain and the liquid equivalent of frozen and freezing precipitation (e.g., snow, sleet, freezing rain, and hail)
- 5. annual total snowfall in inches ~150[bib]975
- 6. annual average for MI ~46 days
- 7. annual average ~170 days (since 1980)
- 8. Water temperatures will reach 10ºC (50ºF) in the spring 10-12 days earlier. Water temperatures will cool to 10ºC in the fall 15-17 days later.
- 9. ice exists between 77 to 115 days per cold-season (1950-95); 70% surface coverage at winter maximum