| Temp. | Wind | ||
|---|---|---|---|
| degrees F | 15 mph | 30 mph | 40 mph |
| 30 | 11 | -2 | -4 |
| 20 | -5 | -18 | -22 |
| 10 | -18 | -33 | -36 |
| 0 | -33 | -49 | -54 |
| -10 | -45 | -63 | -69 |
| -20 | -60 | -78 | -87 |
| -30 | -70 | -94 | -101 |
| -40 | -85 | -109 | -116 |
| Need doctor | I |
| Need medical supplies | II |
| Need food and water | F |
| Need fuel | L |
| International distress signal | SOS |
Ice dams are usually a problem only on cold days when the roof is warmer than the eave overhang. On warm days the snow melts at the same rate on the eaves and water runs off freely.
To prevent ice dams:
Snow damage is more common to shrubs than to trees because snow depth often equals or exceeds shrub height. Evergreen shrubs are more easily damaged than deciduous shrubs because there is more foliage surface for snow accumulation.
To remove heavy snow accumulations:
Often snow damage to evergreens is not apparent until the following spring as a broken branch will retain its green color until warm weather.