Minnesota MSHSL Heat Policy and WBGT Guidelines
The Minnesota State High School League (MSHSL) sets heat limits for high school athletics by Wet Bulb Globe Temperature (WBGT). Here are the activity limits at each level, and how Sports Safe applies them to your fields.
Outdoor practice stops (Northern Minnesota)
83.5°F WBGT and above
Outdoor practice stops (Southern Minnesota)
87.1°F WBGT and above
Minnesota WBGT activity chart
MSHSL publishes separate charts for northern and southern Minnesota, and the northern chart is much stricter. Sports Safe asks which applies to each field, and uses the northern chart until you answer. Check with the MSHSL which chart applies to your school.
Northern Minnesota
No Flag
Under 73.5°F
Practice limit: None stated
Normal activities. At least three separate rest breaks each hour, minimum 3 minutes each.
Green Flag (low)
73.5 to 78.4°F
Practice limit: None stated
Caution for intense or prolonged exercise. Watch at-risk players carefully. At least three separate rest breaks each hour, minimum 4 minutes each.
Yellow Flag (moderate)
78.5 to 81.4°F
Practice limit: 2 hours
Maximum practice time is 2 hours. All sports: at least four separate rest breaks each hour, minimum 4 minutes each.
Equipment: Football: helmet, shoulder pads and shorts only. If the WBGT rises to this level during practice, players may continue in football pants without changing to shorts.
Red Flag (high)
81.5 to 83.4°F
Practice limit: 1 hour
Maximum practice time is 1 hour. 20 minutes of rest breaks distributed through the hour of practice.
Equipment: No protective equipment may be worn, and there may be no conditioning activities.
Black Flag (extreme)
83.5°F and above
Practice limit: No outdoor practice
No outdoor workouts, and no non-air-conditioned indoor workouts. Delay practice until a cooler WBGT level is reached.
| WBGT | Level | Practice limit | What the chart says |
|---|---|---|---|
| Under 73.5°F | No Flag | None stated | Normal activities. At least three separate rest breaks each hour, minimum 3 minutes each. |
| 73.5 to 78.4°F | Green Flag (low) | None stated | Caution for intense or prolonged exercise. Watch at-risk players carefully. At least three separate rest breaks each hour, minimum 4 minutes each. |
| 78.5 to 81.4°F | Yellow Flag (moderate) | 2 hours | Maximum practice time is 2 hours. All sports: at least four separate rest breaks each hour, minimum 4 minutes each. Equipment: Football: helmet, shoulder pads and shorts only. If the WBGT rises to this level during practice, players may continue in football pants without changing to shorts. |
| 81.5 to 83.4°F | Red Flag (high) | 1 hour | Maximum practice time is 1 hour. 20 minutes of rest breaks distributed through the hour of practice. Equipment: No protective equipment may be worn, and there may be no conditioning activities. |
| 83.5°F and above | Black Flag (extreme) | No outdoor practice | No outdoor workouts, and no non-air-conditioned indoor workouts. Delay practice until a cooler WBGT level is reached. |
Southern Minnesota
No Flag
Under 77.1°F
Practice limit: None stated
Normal activities. At least three separate rest breaks each hour, minimum 3 minutes each.
Green Flag (low)
77.1 to 82.0°F
Practice limit: None stated
Caution for intense or prolonged exercise. Watch at-risk players carefully. At least three separate rest breaks each hour, minimum 4 minutes each.
Yellow Flag (moderate)
82.1 to 85.0°F
Practice limit: 2 hours
Maximum practice time is 2 hours. All sports: at least four separate rest breaks each hour, minimum 4 minutes each.
Equipment: Football: helmet, shoulder pads and shorts only. If the WBGT rises to this level during practice, players may continue in football pants without changing to shorts.
Red Flag (high)
85.1 to 87.0°F
Practice limit: 1 hour
Maximum practice time is 1 hour. 20 minutes of rest breaks distributed through the hour of practice.
Equipment: No protective equipment may be worn, and there may be no conditioning activities.
Black Flag (extreme)
87.1°F and above
Practice limit: No outdoor practice
No outdoor workouts, and no non-air-conditioned indoor workouts. Delay practice until a cooler WBGT level is reached.
| WBGT | Level | Practice limit | What the chart says |
|---|---|---|---|
| Under 77.1°F | No Flag | None stated | Normal activities. At least three separate rest breaks each hour, minimum 3 minutes each. |
| 77.1 to 82.0°F | Green Flag (low) | None stated | Caution for intense or prolonged exercise. Watch at-risk players carefully. At least three separate rest breaks each hour, minimum 4 minutes each. |
| 82.1 to 85.0°F | Yellow Flag (moderate) | 2 hours | Maximum practice time is 2 hours. All sports: at least four separate rest breaks each hour, minimum 4 minutes each. Equipment: Football: helmet, shoulder pads and shorts only. If the WBGT rises to this level during practice, players may continue in football pants without changing to shorts. |
| 85.1 to 87.0°F | Red Flag (high) | 1 hour | Maximum practice time is 1 hour. 20 minutes of rest breaks distributed through the hour of practice. Equipment: No protective equipment may be worn, and there may be no conditioning activities. |
| 87.1°F and above | Black Flag (extreme) | No outdoor practice | No outdoor workouts, and no non-air-conditioned indoor workouts. Delay practice until a cooler WBGT level is reached. |
Key points
- The northern chart stops outdoor workouts at a much lower WBGT than the southern one: 83.5°F compared with 87.1°F in Sports Safe.
- MSHSL's charts put readings of exactly 83.5°F (north) and 87.1°F (south) at the top of Red. Sports Safe treats them as Black, the more protective choice.
- At Black flag, non-air-conditioned indoor workouts are also prohibited.
Common questions
- At what WBGT does outdoor practice stop in Minnesota?
- Using the MSHSL heat policy, Sports Safe stops outdoor practice at 83.5°F WBGT on the Northern Minnesota chart, and at 87.1°F WBGT on the Southern Minnesota chart.
- How long can practice last at each heat level in Minnesota?
- Under the MSHSL heat policy, the practice time limits are: Northern Minnesota chart: Yellow Flag (moderate), 78.5 to 81.4°F: 2 hours; Red Flag (high), 81.5 to 83.4°F: 1 hour. Southern Minnesota chart: Yellow Flag (moderate), 82.1 to 85.0°F: 2 hours; Red Flag (high), 85.1 to 87.0°F: 1 hour. Levels not listed have no time limit stated, and at the top level outdoor practice stops.
- Does Sports Safe use the heat chart for Minnesota automatically?
- Yes. Sports Safe uses the MSHSL charts for fields in Minnesota. It asks whether each field uses the northern or southern chart, and uses the northern chart until you answer. You can choose a different chart for any field in its settings.
How Sports Safe uses the Minnesota chart
Sports Safe estimates WBGT for each of your fields from current weather, checks it against this chart, and alerts you when a field moves into a stricter level. On the Organization plan, coaches can keep a timestamped log of meter readings and the actions taken.
An app estimate supports your decisions but is not a WBGT meter. Where your association requires readings from an approved instrument, use one for the reading of record.
Source
Checked against the MSHSL's north and south WBGT chart as reproduced by the National Weather Service Twin Cities office, because the MSHSL's own site was not serving its policy. View the source. Last reviewed October 3, 2026.
Sports Safe is not affiliated with or endorsed by the Minnesota State High School League. Policies change, so always confirm the current rules with your association and follow your school's emergency action plan.