On this page · 8 sections
What does the MHSAA require?
Section 7.9.4 of the 2026-27 MHSAA Handbook says the MHSAA Sports Medicine Advisory Committee mandates WBGT readings for determining the safety of outdoor activities, and points schools to the guidelines on misshsaa.com. A violation is penalized as if the school were practicing out of season.
The MHSAA guidance lists free smartphone apps that give WBGT readings, so a dedicated instrument is not required. As readings rise, practice is shortened and rest and hydration breaks increase. The bands do not remove the need for a cold tub at every outdoor practice, since some athletes reach heat stress earlier than others.
WBGT is mandated
Handbook 7.9.4: WBGT readings decide whether outdoor activity is safe. A violation is penalized like practicing out of season.
The reading
A WBGT instrument or one of the free smartphone apps the MHSAA guidance names: WeatherBug, Google Weather (Android), Carrot Weather, Weather FX.
Cold tub
Available at every outdoor practice, whatever the band. Suspected heat stroke: immerse to the chest for at least 20 minutes, then transport.
Lightning detectors
Handbook 7.9.1 requires schools to provide lightning detectors for all athletic events held outside.
The MHSAA WBGT threshold table
Five bands, read in degrees Fahrenheit: one table for the whole state. The row colour follows the Flash alert scale your athletic trainers already see in the app.
| WBGT (°F) | Activity limit | Rest breaks | Football equipment |
|---|---|---|---|
| Under 82.0 | Normal activities | At least three separate rest breaks each hour with a minimum duration of 3 minutes each during the workout | None listed |
| 82.0 – 86.9 | Use discretion for intense or prolonged exercise; watch at-risk players carefully | At least three separate rest breaks each hour with a minimum duration of 4 minutes each | None listed |
| 87.0 – 89.9 | Maximum practice time is 2 hours | At least four separate rest breaks each hour with a minimum duration of 4 minutes each | Players are restricted to helmet, shoulder pads, and shorts during practice, and all protective equipment must be removed during conditioning activities |
| 90.0 – 92.0 | Maximum practice time is 1 hour | There must be 20 minutes of rest breaks distributed throughout the hour of practice | No protective equipment may be worn during practice, and there may be no conditioning activities |
| Over 92.0 | No outdoor workouts. Delay practice until a cooler WBGT level is reached | — | — |
Source: MHSAA, "Using WetBulb Globe to Modify Activities", WBGT activity guidelines and rest break guidelines (misshsaa.com), referenced by 2026-27 MHSAA Handbook 7.9.4; checked 15 Oct 2026. Ranges as printed. If the WBGT rises into 87.0–89.9 during practice, football players may continue to work out wearing football pants without changing to shorts.
Where does Flash fit?
Flash is a forecast for planning, not an on-site meter: MHSAA compliance uses the WBGT reading your school takes. Flash's 6-hour WBGT outlook tells you at 1 pm what the 4 pm reading is likely to be, so you can move practice instead of cancelling it.
Heat: plan, don't cancel
The outlook runs per field for every hour of the afternoon, against the five MHSAA bands. Shift the start, swap the equipment plan or go indoors before the cars arrive.
Lightning: up to 60 minutes ahead
Strike-level prediction on a 1×1 km cell, refreshed every 2 minutes. Up to 99.6% lightning prediction accuracy on a one-hour window, measured against NLDN ground-truth strikes — method published.
Accuracy methodReturn to play: the all-clear timer
After the last strike inside your radius, Flash runs your policy's all-clear timer and logs it, so play resumes on evidence.
Weather Command Center
Flash Heat and WBGT prediction 6-hour WBGT outlook, heat index, air temperature and dew point per 1×1 km cell
What does a planning day look like?
Illustrative example · Not live weather — the readings are examples, the rules are the MHSAA's
6:15 pm · The reading that decides the day
The band you land in sets the clock, the breaks and the pads.
Flash 6-hour WBGT outlook for the practice field: 86 by 3 pm, into 87.0–89.9 by 4 pm. The athletic director flags the football session.
Decision: run at 4 pm under the 2-hour cap with four 4-minute breaks an hour, or push to 6:30 pm. The AD pushes. The bus, the trainers and the parents hear now, not at 3:45.
WBGT reading before practice: 84.6, the 82.0–86.9 band. Three 4-minute breaks per hour go on the plan and the cold tub is filled on the sideline.
Flash lightning alert: a strike is predicted inside the site radius within the next 60 minutes. The field clears.
Last strike inside the radius. Flash starts the all-clear timer.
All clear. Practice resumes; the alert log records who was warned, when, and when play returned.
What should the athletic director keep on file?
The MHSAA guidance does not set a record-keeping form, but Handbook 7.9.4 penalizes a violation as practicing out of season. Keeping these together means a question from the MHSAA, the district or a parent is answered from one folder.
- WBGT readings with times, and whether each came from an instrument or a smartphone app.
- The band each reading fell in and the decision it triggered: practice time, rest breaks, football equipment.
- The cold tub set-up for each outdoor practice.
- The lightning detector used at outdoor events, as Handbook 7.9.1 requires.
- The Flash alert log: lightning alerts, who was notified, the all-clear, and the 6-hour outlook the schedule decision was based on.
Which other states publish WBGT policies?
Every state page follows this template: verified thresholds, the reading cadence, what to keep on file, and where the WBGT forecast fits.
State by state
Same instrument, different bands — the WBGT forecast travels with you.
- Georgia (GHSA)
- Texas (UIL)
- Florida (FHSAA)
- Arizona (AIA)
- Arkansas (AAA)
- Colorado (CHSAA)
- Hawaii (HHSAA)
- Illinois (IHSA)
- Kansas (KSHSAA)
- Massachusetts (MIAA)
- Missouri (MSHSAA)
- Nevada (NIAA)
- New Hampshire (NHIAA)
- New Mexico (NMAA)
- North Carolina (NCHSAA)
- Ohio (OHSAA)
- West Virginia (WVSSAC)
- Oklahoma (OSSAA)
- Alabama (AHSAA)
- California (CIF)
- Connecticut (CIAC)
- Iowa (IHSAA / IGHSAU)
- Kentucky (KHSAA)
- Louisiana (LHSAA)
- Minnesota (MSHSL)
- Nebraska (NSAA)
- New Jersey (NJSIAA)
- New York (NYSPHSAA)
- South Carolina (SCHSL)
- South Dakota (SDHSAA)
- Utah (UHSAA)
- Vermont (VPA)
- Virginia (VHSL)
- Washington (WIAA)
- Wisconsin (WIAA)
Sources
- MHSAA — 2026-27 Handbook, 7.9.1 and 7.9.4, Safety Requirements and Recommendations: WBGT readings mandated, penalty, lightning detectors. Checked 15 Oct 2026.misshsaa.com/wp-content/uploads/2026/06/2026-27-MHSAA-Handbook-Final-V6.pdf (opens in a new tab)
- MHSAA — Using WetBulb Globe to Modify Activities (July 2026), with the WBGT activity guidelines and rest break guidelines chart and the smartphone apps listed. Checked 15 Oct 2026.misshsaa.com/2026/07/13/using-wbg-to-modify-activities/ (opens in a new tab)
- MHSAA — SMAC Heat Update 2026 (reviewed August 2026): rest breaks, WBGT-based schedule changes, cold-water immersion. Checked 15 Oct 2026.misshsaa.com/2026/08/10/smac-heat-update-2026/ (opens in a new tab)
MHSAA documents are published at misshsaa.com (opens in a new tab).
Frequently asked
No. MHSAA compliance is decided by the WBGT reading your school takes, from an instrument or one of the apps the MHSAA lists. Flash's 6-hour outlook tells you where that reading is heading — a scheduling tool, not a compliance instrument.
Yes. The MHSAA guidance names free smartphone apps that give WBGT readings — WeatherBug, Google Weather (Android), Carrot Weather and Weather FX — so schools do not have to buy a dedicated instrument.
The limits of the new band apply. If the reading reaches 87.0–89.9 during practice, football players may keep working out in football pants without changing to shorts.
Handbook 7.9.4 says a violation is penalized as if the school were practicing out of season.