File Formats and Samples

SILO data are available in a range of customisable formats.

Point datasets

A continuous daily time series of data at either recording stations or grid points across Australia.

Point datasets are available in a range of predefined formats tailored for use in popular models and decision support systems:

 

Data format Description Sample Data

Standard

(Standard)

Format is widely used for biophysical modelling. It provides data for: daily rainfall, maximum and minimum temperature, pan evaporation, solar radiation, vapour pressure, and relative humidity at the times of maximum and minimum temperature. Station
Grid point  

Standard including FAO56 reference evapotranspiration (short crop ETo)

(FAO56)

Similar to the Standard format, but also includes potential evapotranspiration (ETo). The ETo estimates are calculated using the FAO Penman-Monteith formula with a default wind value of 2 m/s. The Penman-Monteith formula also requires radiation as an input. Radiation is derived from cloud oktas and hours of sunshine duration using the procedure documented in Zajaczkowski et al.(2013).

Note: This is a short crop version of the Penman-Monteith equation. As per Food and Agriculture Organization of the United Nations (FAO), paper “Crop evapotranspiration – Guidelines for computing water requirements – FAO Irrigation and drainage paper 56.

see our References section for further information.

Station
Grid point 

APSIM

(APSIM Model)

Format is for use with the Agricultural Production Simulator (APSIM). Station
Grid point 

P51

(P51 for GRASP and MEDLI models)

Format is for use with the Grass Production (GRASP) model and the Model for Effluent Disposal and Land Irrigation (MEDLI) V2 model.

Note: this format is used by many biophysical modellers as it contains the core variables in a mimimal format.

Station
Grid point 

RAINMAN Streamflow 4.3 

(RAINMAN)

Format is for use with the RAINMAN application. It provides data for rainfall, maximum and minimum temperatures, Class A pan evaporation, vapour pressure and solar radiation. The data for each variable are in separate files. It also includes instructions in a Readme text file. Station
Grid point 

Rainfall only

(Rain Only)

Format contains daily rainfall; data are not provided for any other variable. Station
Grid point 
 

Standard including ASCE reference evapotranspiration (tall crop ETo)

(ASCE Penman Monteith for tall crop)

Similar to the Standard format, but also includes potential evapotranspiration (ETo). The ETo estimates are calculated using the ASCE Penman-Monteith formula with a default wind value of 2 m/s. The Penman-Monteith formula also requires radiation as an input. Radiation is derived from cloud oktas and hours of sunshine duration using the procedure documented in Zajaczkowski et al.(2013).

Note: This is a version of Penman-Montheith designed for taller crops by the American Society of Civil Engineers.

see our References section for further information.

Station
Grid point 

Monthly

(Monthly summary)

Format provides: (i) monthly totals for rainfall and evaporation; and (ii) monthly means for maximum and minimum temperatures, solar radiation and vapour pressure. Station
Grid point 

Morton's

(All Morton hydrological Evapotranspirations)

Similar to the Standard format, but also includes Morton's estimates of the following: (i) evaporation over shallow lakes; (ii) potential evapotranspiration over land; (iii) actual evapotranspiration over land; and (iv) wet environment areal evapotranspiration over land. Station
Grid point 

Evaporation*
combination

(Synthetic Pan before 1970, Pan evaporation after 1970)

Similar to the Standard format, but includes an additional column (denoted Evap_Sp) containing either: (i) a synthetic estimate of pan evaporation (1/1/1889 to 31/12/1969); or (ii) observed (or patched) Class A pan evaporation (1/1/1970 to present). Station
Grid point 

Evaporation*
comparison

(Synthetic Pan comparison)

Similar to the Standard format, but includes an additional column containing a synthetic estimate of pan evaporation (1/1/1889 to present). This format differs from the "Evaporation combination" format in that all data in the additional column (denoted Span) are synthetic estimates. Station
Grid point 

CenW Forest Growth Model

(CenW Forest Growth Model)

Format is for use with the CenW Forest Growth Model. Station
Grid point 

Programmer's data for comparison with ASCE Reference Evapotranspiration

(Comparison including ASCE-PM)

Similar to the “Programmer's data for comparison” format, but also includes the ASCE’s tall crop estimate of potential evapotranspiration (ETo).

Station
Grid point

Programmer's data for comparison

(Comparison)

Format contains most variables provided by SILO: the default variables included in the Standard format as well as:
  • FAO56 (short crop) estimate of potential evapotranspiration (using a wind speed of 2m/s);
  • synthetic evaporation;
  • Morton's estimates of evaporation/evapotranspiration; and
  • mean sea level pressure.

    This format may be useful for new clients wishing to evaluate our products.
Station
Grid point 
Point data are also available in customisable CSV and JSON formats:
JSON Contains data for only those variables selected by the user. Station
Grid point  
CSV Contains data for only those variables selected by the user. Station
Grid point  

 * Please note, evaporation data are provided with a day-shift applied. For example: evaporation data for 31/01/2017 were actually reported on 01/02/2017 (day after). The shift to the previous day is applied because most (15 hours) of the recorded evaporation occurs in the previous day (measurement is taken at 9 am). The day-shift is applied to the Patched Point Data and Grid point formats and also to the evaporation combination format (with the use of synthetic evaporation data). However, the observed evaporation data (class A pan) are interpolated without a day-shift applied and gridded datasets are not day-shifted. 

Many of the data formats share a common structure consisting of two blocks of information:

1. Descriptive block.


Several formats include a header describing the data. The metadata in the header is structured as follows:

  • All lines start with a double quote ("), or exclamation mark (!)
  • There are two sub-sections:
  1. Information for spreadsheet users (approximately 7 lines of text). The first line contains dummy data to enable a spread sheet program to sense the data format; and
  2. Information about the data requested: Approximately 20 lines of text containing:
    1. For DataDrill datasets:
      i. the latitude and longitude of the location; and
      ii. the user supplied reference (a single word, up to 10 characters long).
    2. For Patched Point datasets:
      i. the station details, including the latitude and longitude
    3. The elevation at the location of interest
    4. The date that the data were extracted from the database; an
    5. A link to the SILO webpage where the user can find documentation and notices.

2. Data block


The data block typically contains:

  • A line containing a label for each column of data appearing in the data block. The column titles are space separated, one word per data column. The line is of the form:
    Date Variable_1 Variable_1_Source Variable_2 Variable_2_Source ··· Variable_n Variable_n_Source
    where Variable_n_Source is the source code for variable n.
  • A line containing the units for each column of data. The units are space separated, one word per data column, and are enclosed in parentheses ().
  • Lines of data. Each line starts with a date in yyyymmdd format. Therefore the first character is a 1 or 2. The data block continues to the end of the file i.e. there is no 'marker' to signify the end.

Gridded datasets

Gridded daily climate surfaces which have been derived either by splining or kriging the observational data.

The data are provided in NetCDF format and arranged in annual blocks. Each annual file contains all of the daily grids for a given year and variable (or 12 monthly grids in the case of monthly rainfall).

Example demonstrating how the NetCDF data can be viewed, manipulated and analysed are provided on the gridded data page.

Last updated: 9 July 2019