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Daily Climate Records and Matched Normal Comparisons

Summarize daily climate coverage, rain and degree days, then compare observations with supplied normals on the same matched calendar dates.

Use this result well

Inputs that matter
Station and daily reporting basis, First date, Last date, Heating/cooling degree-day base (°C), and 5 more
Output to expect
Daily climate coverage and degree days, Matched observed and normal daily values
  • Check the units and required inputs before comparing results.
  • Keep the assumptions with a copied result so you can reproduce the calculation later.
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Reference & details

How it works

Daily climate coverage and degree days

Summarize actual daily minimum/maximum temperatures and liquid-equivalent precipitation for an explicit period. Keep absent dates, missing values and traces separate; show degree-day totals only for days with both temperatures.

Daily mean estimate = (Tmin+Tmax)/2; HDD = max(base−mean,0); CDD = max(mean−base,0). Precipitation sum retains separate trace and missing counts.

Matched observed and normal daily values

Compare a supplied daily series with a documented reference normal on exactly matching calendar dates. Report common-date coverage and differences of means or sums; no normal is invented from the short observed sample.

Matched anomaly = observed − reference for each paired date. Mean anomaly = mean(matched differences); sum anomaly = sum(matched differences).

Updated: September 2026

Example Scenarios

Inspect the example and its input basis, then substitute your own documented measurements or matched cases.

Station and daily reporting basis: Example station, local daily cutoff documentedFirst date: 2026-09-01Last date: 2026-09-03Heating/cooling degree-day base (°C): 18Daily records: 2026-09-01 | 10 | 20 | 0 | checked 2026-09-02 | 12 | 22 | T | trace 2026-09-03 | 14 | 26 | 2.5 | checked

→ 17.333333°C mean of 3 daily mean estimates

Inspect the example and its input basis, then substitute your own documented measurements or matched cases.

Station and daily reporting basis: Example station, fixed daily cutoffFirst date: 2026-09-01Last date: 2026-09-03Reference normal, variable and unit: Illustrative daily mean temperature normals, °C; replace with documented source and baseline periodComparison summary: meanMatched daily values: 2026-09-01 | 20 | 18 | same station 2026-09-02 | 22 | 19 | same station 2026-09-03 | M | 20 | missing observation

→ 2.5 matched mean anomaly (2/3 days)

Common Mistakes to Avoid

Mixing observation and model inputs

Use the exact units, timestamp, level and measurement or model basis stated by the selected mode. A similar quantity from another instrument or product is not automatically interchangeable.

Treating an illustrative case as a measurement

Replace the example with your own sourced inputs. Retain missing values and method limits, and keep raw source data alongside a saved calculation.

FAQ

Summarize actual daily minimum/maximum temperatures and liquid-equivalent precipitation for an explicit period. Keep absent dates, missing values and traces separate; show degree-day totals only for days with both temperatures. Compare a supplied daily series with a documented reference normal on exactly matching calendar dates. Report common-date coverage and differences of means or sums; no normal is invented from the short observed sample.

Retain the station or profile identity, observation or issue/valid time, measurement units, quality flags, source and stated method. Missing values, trace precipitation and known zeros have different meanings.

Save weather case keeps an explicit local record. Copy MD includes current inputs and notes; Download CSV includes the current result breakdown. Keep portable copies separately and retain raw source data.

About Daily Climate Records and Matched Normal Comparisons

Summarize actual daily minimum/maximum temperatures and liquid-equivalent precipitation for an explicit period. Keep absent dates, missing values and traces separate; show degree-day totals only for days with both temperatures. Compare a supplied daily series with a documented reference normal on exactly matching calendar dates. Report common-date coverage and differences of means or sums; no normal is invented from the short observed sample.