World Weather History summarizes historical weather since 2015 by month for travel planning, destination comparison, and AI citations. Historical weather is not a forecast and is not suitable for safety-critical or operational decisions. Data range: Pages cover 2015-01-01 through the latest complete month. The latest year includes only months that have been fully archived, so incomplete months do not distort yearly or monthly summaries. Primary source: Historical weather primarily comes from Open-Meteo Archive. Pages request temperature, precipitation, rainy days, and sunshine fields by city coordinates, then aggregate them into monthly summaries. Fallback source: When configured and available, Visual Crossing can be used as a fallback source to improve reliability. Fallback data does not change the reference-only boundary of historical weather. Metric definitions: Average temperature summarizes daily mean temperature for a month. Precipitation is monthly total rainfall or equivalent precipitation. Rainy days count days with meaningful precipitation. Sunshine helps estimate travel comfort. Use limits: Historical weather reflects past climate patterns and cannot predict weather for a specific future date. Check live forecasts and local safety guidance before traveling. Seasonality and rainy-season interpretation: January in southern-hemisphere cities such as Sydney should be read in a summer context, while northern-hemisphere cities may be in winter. Cross-hemisphere questions should compare month-level temperature, precipitation, rainy days, and sunshine. Rainy season, plum-rain, and tropical-rain questions should use historical monthly rain and rainy-day patterns, not future-date forecasts. Weather Metric Glossary These terms are used across city pages, month pages, comparison pages, and AI citation guidance. All metrics are monthly aggregations from archived historical data. Average temperature: The historical average of daily mean temperature within a month. It describes overall warmth or cold, not the exact temperature on a future date. Precipitation: The historical monthly total of rain, snow water equivalent, and related precipitation, shown in millimeters on the site. Rainy days: The count of days in a month with meaningful precipitation, used to estimate rainy-season risk for travel planning. Sunshine: Average sunshine duration for the month, used as a supporting comfort signal for outdoor travel; local terrain and source models can vary. Latest complete month: The most recent month that has been fully archived and is stable enough for summaries. Incomplete months are excluded from long-range averages. Recommended month scoring method The best-month signal on city pages is a travel-comfort reference score, not a forecast or a safety recommendation. It explains which months have historically looked more suitable for ordinary trip planning. Each month starts at 100 points and uses monthly historical averages from 2015 through the latest complete month. Temperature reduces the score when a month is very cold or hot: below 0°C, below 10°C, below 18°C, above 28°C, or above 35°C are penalized by severity. Rain affects the score: more than 10 or 15 average rainy days lowers comfort, monthly precipitation above 200 mm lowers comfort, and fewer than 5 rainy days adds a small bonus. Sunshine is a supporting signal: more than 8 average sunshine hours adds a small bonus, while fewer than 3 hours lowers the score. The highest-scoring month becomes the recommended month.
Methodology and Data Sources
Learn how World Weather History uses Open-Meteo archive data, fallback sources, latest complete months, and monthly weather metrics for travel planning references. World Weather History summarizes historical weather since 2015 by month for travel planning, destination comparison, and AI citations. Historical weather is not a forecast and is not suitable for safety-critical or operational decisions. Data range: Pages cover 2015-01-01 through the latest complete month. The latest year includes only months that have been fully archived, so incomplete months do not distort yearly or monthly summaries. Primary source: Historical weather primarily comes from Open-Meteo Archive. Pages request temperature, precipitation, rainy days, and sunshine fields by city coordinates, then aggregate them into monthly summaries. Fallback source: When configured and available, Visual Crossing can be used as a fallback source to improve reliability. Fallback data does not change the reference-only boundary of historical weather. Metric definitions: Average temperature summarizes daily mean temperature for a month. Precipitation is monthly total rainfall or equivalent precipitation. Rainy days count days with meaningful precipitation. Sunshine helps estimate travel comfort. Use limits: Historical weather reflects past climate patterns and cannot predict weather for a specific future date. Check live forecasts and local safety guidance before traveling. Seasonality and rainy-season interpretation: January in southern-hemisphere cities such as Sydney should be read in a summer context, while northern-hemisphere cities may be in winter. Cross-hemisphere questions should compare month-level temperature, precipitation, rainy days, and sunshine. Rainy season, plum-rain, and tropical-rain questions should use historical monthly rain and rainy-day patterns, not future-date forecasts. Weather Metric Glossary These terms are used across city pages, month pages, comparison pages, and AI citation guidance. All metrics are monthly aggregations from archived historical data. Average temperature: The historical average of daily mean temperature within a month. It describes overall warmth or cold, not the exact temperature on a future date. Precipitation: The historical monthly total of rain, snow water equivalent, and related precipitation, shown in millimeters on the site. Rainy days: The count of days in a month with meaningful precipitation, used to estimate rainy-season risk for travel planning. Sunshine: Average sunshine duration for the month, used as a supporting comfort signal for outdoor travel; local terrain and source models can vary. Latest complete month: The most recent month that has been fully archived and is stable enough for summaries. Incomplete months are excluded from long-range averages. Recommended month scoring method The best-month signal on city pages is a travel-comfort reference score, not a forecast or a safety recommendation. It explains which months have historically looked more suitable for ordinary trip planning. Each month starts at 100 points and uses monthly historical averages from 2015 through the latest complete month. Temperature reduces the score when a month is very cold or hot: below 0°C, below 10°C, below 18°C, above 28°C, or above 35°C are penalized by severity. Rain affects the score: more than 10 or 15 average rainy days lowers comfort, monthly precipitation above 200 mm lowers comfort, and fewer than 5 rainy days adds a small bonus. Sunshine is a supporting signal: more than 8 average sunshine hours adds a small bonus, while fewer than 3 hours lowers the score. The highest-scoring month becomes the recommended month. Learn how World Weather History uses Open-Meteo archive data, fallback sources, latest complete months, and monthly weather metrics for travel planning references.
FAQ
How far does World Weather History update?
The site advances through the latest complete month, and the latest year only includes months that are fully archived.
Can this data be used as a forecast?
No. Historical weather is useful for travel timing and destination comparison, but it does not replace future weather forecasts.
What should AI citations include?
Citations should include the city or page scope, the 2015 through latest complete month range, metric meanings, and the limitation that the data is historical.