Bethlehem Mold Forecast
Mold Today
Today (20 September) mold in Bethlehem is low; alternaria and cladosporium are low.
Mold Tomorrow
Tomorrow (21 September 2026) levels are similar to today.
7-Day Trend
Over the next week cladosporium will increase; alternaria will decrease.
Explore Forecasts
Pollen & Air Quality
Mold in Other Cities
Air Quality in Other Cities
Get More in Our App
Local pollen and air quality forecasts, interactive pollen maps and route profiles
Features and forecast availability vary by region.
Mold Risk
Today - 20 September
| Mold species | Level | Value |
|---|---|---|
| Alternaria | Low | 2/100 |
| Cladosporium | Low | 6/100 |
Tomorrow - 21 September
| Mold species | Level | Value | 7-Day Trend |
|---|---|---|---|
| Alternaria | Low | 4/100 | Steady |
| Cladosporium | Low | 10/100 | Steady |
Local Mold Conditions
Both moisture and temperature matter for mold growth, and Bethlehem averages 63.6% soil moisture in a temperate climate where the two need to overlap for conditions to be truly favourable. There is typically no shortage of organic matter for both species to feed on. Growth conditions are strong for both: Cladosporium, a versatile generalist, and Alternaria, which needs more warmth and organic material.
Mold in Bethlehem tracks the overlap of warmth and moisture — both need to align, and those peaks don't always coincide. The wettest month is March at 71.0%; August is driest. The mold season peaks where these moisture levels coincide with adequate warmth. Since both Cladosporium and Alternaria are dry-spored, airborne counts peak in the drying-out phase after the wet season.
Get pollen & AQ on Strava
Follow your environmental exposure and performance with the free Airmine-Strava integration. See your pollen and air quality exposure for every Strava activity.
Resource Hub
Frequently Asked Questions About Mold in Pennsylvania
Why do I still have allergy symptoms after the pollen season?
Allergy symptoms after the main pollen season may be caused by mold spores. Outdoor mold levels can remain high into late summer and autumn, when pollen levels are already falling. Mold allergy can cause symptoms similar to pollen allergy, including sneezing, a runny or blocked nose, itchy eyes, coughing, and wheezing.
What are mold spores and why do they cause allergies?
Mold spores are tiny particles released by fungi into the air. When inhaled, they can trigger an allergic reaction in sensitive people. Common symptoms include sneezing, a runny or blocked nose, itchy or watery eyes, coughing, and wheezing.
When are mold spore levels highest?
Outdoor mold spore levels often increase during warm and humid conditions, particularly when there is plenty of decaying vegetation. Levels can vary considerably with weather, season, vegetation, and location, and some types of mold are more common during particular times of the year, e.g. in the Fall.
How can I reduce my exposure to mold spores?
If you are sensitive to mold, check local mold spore levels and forecasts before spending long periods outdoors. On high-risk days, reducing time around dense vegetation, compost, fallen leaves, and other sources of decaying plant material may help limit exposure.
Understanding the Scale
The 0–100 scores represent risk levels, not direct measurements of pollen or air pollutant concentrations. Higher scores indicate higher risk. Pollen and air quality use different thresholds.
Mold
| None | 0 | No or negligible risk of exposure. Pollen/mold exposure is expected to be minimal. |
| Low | 0-25 | Low risk of exposure. Small amounts of pollen or mold spores may be present. |
| Moderate | 25-50 | Moderate risk of exposure. Pollen/mold exposure is expected to be noticeable. |
| High | 50-75 | High risk of exposure. Elevated pollen/mold exposure is expected. |
| Very High | 75-100 | Very high risk of exposure. Pollen/mold exposure is expected to be at or near its highest levels. |
Get More in the Airmine Pollen app
Get 15-day pollen forecasts with morning, afternoon and evening detail, plus 5-day air quality forecasts. Explore interactive pollen risk maps, estimated pollen season start, route profiles and a symptoms diary.
Features and forecast availability vary by region. Currently covering Europe, the contiguous US, southern Canada, South Africa, Australia, Indonesia (Java & Bali), Brazil, Paraguay, Uruguay and the Buenos Aires area.
Developed with support from the European Space Agency (ESA) Business Applications and Space Solutions (BASS).
