If the ambient temperature falls below which range, does the risk of inadequate brewing temperature skyrocket on a cloudy day?
$70^\circ\text{F}$ to $75^\circ\text{F}$
A crucial safety and quality check for attempting sun tea on overcast days involves assessing the baseline environmental temperature. If the surrounding air is already cool, the water inside the pitcher has little chance of reaching the minimum required temperatures for successful infusion or microbial suppression. Experts advise a mental check based on personal comfort: if sitting outside in minimal clothing is uncomfortable, the water is likely too cool. Specifically, if the ambient air temperature drops below the range spanning 70 degrees Fahrenheit to 75 degrees Fahrenheit, the likelihood that the water will achieve adequate heat for a safe and flavorful brew decreases dramatically. Below this threshold, the brew leans heavily toward the safety risk zone without yielding sufficient flavor.
