NIWA generates daily and hourly data as part of the Climate Station Network. Parameters vary station to station with standard parameters as follows. Note: some parameters (evaporation, radiation) have different types.
| Parameter | Measurement Period | Variables included | Data Types | Notes |
|---|---|---|---|---|
| Pressure | Average for preceding one minute (automated observations) | Mean sea level pressure [hPa] Station pressure [hPa] | ||
| Screen Observations | Average for preceding one minute (automated observations) | Air temperature (dry bulb) [Deg C] Wet bulb temperature [Deg C] Dew point temperature [Deg C] Relative humidity [percent] | ||
| Wind | Mean over preceding interval (as per field PERIOD) | Wind speed [m/s] Direction [Deg T] | Deg T = Degrees True = Degrees from true north numbered clockwise from 0 to 360; 990 = Variable 0 = Calm Direction data is rounded to the nearest 10 degrees for data sources M, S | |
| Rain | Cumulative over preceding interval (as per field PERIOD) | Rain [mm] Deficit [mm] Runoff [mm] | “Deficit” and “Runoff” are calculated by a water balance scheme that updates daily records with estimates of soil moisture deficit and runoff. Runoff occurs when the deficit becomes negative and, at the other extreme, the deficit can become no greater than the available water capacity of the soil. The deficit changes from day to day according to what rain fell and how much PET occurred. Any rain decreases the deficit and PET increases the deficit but for deficits greater than half the capacity of the soil the PET is linearly decreased by the proportion that the deficit is greater than half capacity. Calculations are based on field experiments using medium silt loam fully grassed soils, with available water capacity determined at 150 mm. Runoff is assumed to occur when the soil moisture content exceeds Field Capacity (typically about 38% by volume). The term runoff is taken to encompass both surface runoff and gravitational drainage through the soil profile. | |
| Evaporation | Cumulative over preceding interval (as per field PERIOD) | Evaporation [mm] | Sunken Pan (S) Raised Pan (R) Penman Open Water Evaporation (O) Penman PET (P) Priestly Taylor PET (T) | |
| Sunshine | Cumulative over preceding interval (as per field PERIOD) | Sunshine [hrs] | ||
| Radiation | Cumulative over preceding interval (as per field PERIOD) | Radiation [MJ/m2] | Global (G) Diffuse (F) Direct (R) | |
| Temperature | Max/Min over preceding interval (as per field PERIOD) | Maximum temperature [Deg C] Minimum temperature [Deg C] Grass temperature [Deg C] Mean temperature [Deg C] Mean relative humidity [percent] | ||
| Gust | Maximum over preceding interval (as per field PERIOD) | Wind speed [m/s] Direction [Deg T] | Speed of the highest recorded wind gust during the period of observation.Direction from which the highest wind gust came during the period of observation.For case Frequency=H, origin either E=Environmental Data Recorder, M=Metar:The EDR (Environmental Data Recorder) gives the highest gust speed in the preceding hour, without a direction.The Metar only reports a gust if it is 10 or more knots above the reported mean surface wind in the 10 minutes preceding the report and occurred in the same 10-minute period. The speed in knots is converted to m/s. The direction is not given. | |
| Earth Temperature | Average for preceding one minute (automated observations) | Depth [cm] Temperature [Deg C] | ||
| Soil Moisture | Average for preceding 5 minutes (automated observations) | Depth [cm] Soil moisture [percent] | Expressed as a percentage by volume. |
Data is available for different data sources as described here.
| Source codes | Data Frequency | Notes |
|---|---|---|
| H, E, A | Hourly | Hourly recorded or aggregated data from recorders. |
| M | Hourly | A METAR (Meteorological Aviation Report) is an International Civil Aviation Organization (ICAO) message format. |
| S | 3 or 6 hourly | “SYNOP”: a coded message defined by the World Meteorological Organization (WMO) used for reporting international weather observations typically every three or six hours. |
| D | Daily | Ingested manual daily (near real-time) for various climate products. |
| F | Varying | “Forms”, manual provided station readings. |
| R | Hourly | Data from Rain-Intensity-Gauges (Drop counter). |
| P | Varying | Data obtained from Dines-Pluviograph. |
| Q | Varying | Data from Hydra-Drop-gauge. |
Where can I get the Data?
The data can be obtained from NIWA DataHub
Data Format
- Data is provided as CSV files of individual time series, per parameter, type, and source. Naming convention for the files is: [agentno]_[parameter]_[data type]_[data source code].csv
Data source and data type is described in above tables. - The CSV files contain in addition to the measurements the following fields:
- Observation time UTC (Coordinated Universal Time).
- Data Source: data source code as described in above table.
- Data Type: data type as described in above table.
- PERIOD [hrs]: period in hours over which measurement is taken (e.g. 0.17 denotes 10 minutes).
- Frequency: frequency the measurements are taken at (e.g. hourly, daily).
- The data is “packaged” as zip files for each station and parameter, naming convention for the files is [agentno]_[parameter].zip
