Pollen is released during the hottest part of the day so that the thermals can carry the pollen far and wide. Mold cannot tolerate sunlight so the most efficient mold will go off at the darkest time of the night. That is what mold typically does to us. I will cover these two allergens separately, although the measures used to cope with them are almost identical. The most successful allergy and asthma patients are those who recognize their triggers and avoid them.
Considerable evidence suggests that allergy and asthma are caused, at least in some part, by molds.
If no other triggers have been identified, or if you are controlling known triggers and still have problems, consider molds, even if your allergist found no sensitivity to molds. Common airborne molds are the most often tested for, and the most difficult, because they cannot be controlled. However, there are thousands of mold species, far too many to be included in standard allergy testing. Mutants cannot be tested for. Less common molds are often not tested for, and can be highly allergenic.