San Francisco is a cool marine deployment environment where corrosion relevance is driven more by chloride and persistent humidity than by heat.
Analyze San FranciscoMarine chloride is the primary stressor. Persistent humidity is the secondary driver for reliability and field durability decisions.
CE classes describe overall environmental severity and are not equivalent to ISO corrosivity classes.
A normalized 0-100 matrix showing which exposure mechanisms dominate the deployment environment. Scores describe environmental load intensity, not failure probability.
San Francisco demonstrates that corrosion exposure can be relevant even where heat stress is relatively low.
Marine chloride, fog-prone humidity and limited drying potential can affect exposed metals, connectors, fasteners and enclosure interfaces.
For qualification planning, San Francisco is a useful contrast case to hot-humid cities such as Houston or Singapore because the dominant mechanism is coastal marine exposure rather than temperature.
Climetry-derived indicators summarize environmental severity. ISO-derived indicators estimate material-related atmospheric corrosivity for metals such as carbon steel, zinc, copper and aluminum.
Low heat stress with strong coastal chloride and persistent humidity.
Calibrated California chloride layer indicates strong marine deposition context.
Fog-prone and cool-humid periods can support surface wetness.
CEY10 frequent high-humidity exposure without tropical heat.
CEY10 extreme RH periods occur during fog and cool wet episodes.
Coastal, mild, low heat, strong marine modifier.
Preview profiles show monthly min-max envelopes, P10-P90 percentile bands, and monthly means for the core thermodynamic variables.
Humidity is persistent despite mild temperatures, especially during fog-prone periods.
Thermal stress is low; the climate is dominated by cool marine exposure rather than heat.
Absolute humidity is moderate but drying potential can remain limited near the coast.
Dew point and air temperature can remain close during fog and marine-layer conditions.
These figures are calculated from the local hourly Climetry Environmental Year and translate thermodynamic climate data into engineering-readable duration, cycle and moisture-risk views.
San Francisco's 1 C temperature-duration histogram is calculated from the selected hourly CEY10 source months. It shows how long products experience each outdoor temperature band during the representative year.
The RH duration histogram translates relative humidity into annual exposure hours. It supports moisture-sensitive electronics, coating, connector and enclosure screening.
The joint duration heatmap shows which temperature and humidity combinations occur together. This is more useful for durability screening than separate annual averages.
The psychrometric density view connects dry-bulb temperature with absolute humidity and helps identify moisture-rich operating conditions and drying limitations.
The percentile profile summarizes the representative spread of temperature, dew point, relative humidity, absolute humidity and dew-point margin.
The selected high-risk week highlights periods with elevated humidity, absolute humidity and small dew-point spread. It is a screening view for condensation and moisture-ingress relevance.
Daily temperature-cycle statistics provide engineering input for thermomechanical reliability assessments, enclosure breathing and gasket stress screening.
The cold-week temperature histogram is useful for heating-load screening in temperate and cold climates. In tropical climates it confirms low heating-design relevance.
CE classes summarize humidity, condensation potential, marine influence, pollution context and thermal exposure. They are not ISO 9223 corrosivity classes.
It is useful for identifying persistent moisture exposure relevant to electronics, coatings, connectors, enclosures and atmospheric corrosion screening.
It is derived from temperature, dew point and humidity context. It is a screening indicator, not a measurement on a specific product surface.
San Francisco values are sampled from the updated Climetry California 1.5 km atmospheric transport overlays using 32 wind sectors and corrected diffusion. Chloride is calibrated against regional NADP stations; SOx is rank-valid but magnitude-uncalibrated. ISO-derived corrosivity values are engineering screening estimates for carbon steel, zinc, copper and aluminum, not certified ISO 9223 classifications.
Annual mean sampled at San Francisco from the California 1.5 km atmospheric transport grid with 32 wind sectors.
California chloride calibration: R2=0.409, rho=0.691, n=11 against NADP wet-deposition stations.
Immediate marine exposure is the dominant atmospheric modifier.
Sampled at San Francisco from the California SOx transport screening grid with 32 wind sectors.
EPA SO2 comparison: rho=0.513, p=0.0023, n=33. Absolute magnitude remains uncalibrated.
Approximate ISO 9223-style input categories: time of wetness, chloride deposition and sulphur pollution screening input.
ISO-derived screening estimate: about 10.0 um/year using California 32-sector chloride and SOx context.
ISO-derived screening estimate: about 0.426 um/year; marine chloride is the main driver.
ISO-derived screening estimate: about 0.206 um/year; screening-level atmospheric corrosivity, not certified site classification.
ISO-derived screening estimate: about 0.322 um/year; chloride-sensitive but below severe coastal-tropical levels.
For San Francisco, marine chloride and cool-humid wetness dominate over heat or SOx.
Monthly profiles are derived from the California 2015-2024 atmospheric transport model at the San Francisco grid cell. The layer uses 32-sector ERA5 wind climatology, a 1.5 km target grid and corrected diffusion.
Monthly chloride screening estimates are normalized to the same annual grid-cell mean shown above. The calibrated California layer indicates strong marine chloride exposure at San Francisco, with winter and shoulder-season peaks in the screening profile.
The SOx screening index is lower than chloride exposure. Rank validity is meaningful at regional scale, but absolute magnitude is not calibrated.
The environmental indicators presented on this page are derived from ERA5 climate data.
ERA5 thermodynamic variables have been compared against long-term airport weather station observations across multiple climate regions.
The comparison demonstrates good agreement between ERA5 and measured environmental conditions.
These comparisons evaluate long-term environmental representativeness and not individual weather events.
Monthly thermodynamic comparison against San Francisco International Airport (KSFO) weather observations for 2025.
The full report combines climate classification, corrosion screening, condensation exposure, RH80/RH90 hours, marine context, monthly profiles, and reliability implications.
High humidity and condensation exposure may result in a severe Climetry Exposure Class even if atmospheric metal corrosivity remains moderate. CE classes indicate environmental severity and qualification relevance, not failure probability.
Analyze any location worldwide and compare humidity, condensation and environmental severity.
CE-4 is a Climetry Exposure Class. It describes overall environmental severity for durability screening and qualification support at this location.
No. The page provides environmental exposure screening. Corrosion indicators are engineering screening outputs, not failure probability and not a product-specific lifetime prediction.
The indicators are derived from ERA5 climate data. ERA5 thermodynamic variables have been compared against representative airport weather observations and show good monthly agreement for temperature, dew point and relative humidity.
CE classes describe overall environmental severity. ISO 9223 corrosivity classes describe material-related atmospheric corrosivity categories. They are related but not equivalent.
Climetry uses ERA5 temperature, dew point and pressure fields to derive relative humidity, absolute humidity and environmental exposure indicators for engineering interpretation.
