GB/T 33670-2026Assessment method for annual climatic status (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document replaces GB/T 33670-2017 "Methods for Assessing Climate Years". Compared with GB/T 33670-2017, except for structural adjustments and Aside from editorial changes, the main technical changes are as follows:

a) Change "Annual Temperature Index" to "Temperature Deviation" (see Chapter 4, Chapter 3 of the.2017 edition);

b) Change "Precipitation Year Index" to "Precipitation Deviation" (see Chapter 5, Chapter 4 of the.2017 edition);

c) Change "Climate Year Index" to "Climate Anomaly Level" (see Chapter 6, Chapter 5 of the.2017 edition);

d) The "Climate Year Scale" has been removed (see Chapter 6 of the.2017 edition);

e) The "Method for Calculating Standard Deviation" has been removed (see Appendix A of the.2017 edition);

f) The "Percentile Calculation Method" has been removed (see Appendix B of the.2017 edition);

g) The "Standardized Precipitation Index (SPI) Calculation Method" has been removed (see Appendix C of the.2017 edition). Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents. This document was proposed by the China Meteorological Administration. This document is under the jurisdiction of the National Technical Committee on Standardization of Climate and Climate Change (SAC/TC540). This document was drafted by the National Climate Center and the Institute of Atmospheric Physics, Chinese Academy of Sciences. The main drafters of this document are. Chen Xianyan, Wang Lin, Jiang Yundi, Zeng Hongling, and Wang Rong. The release history of this document and the document it replaces is as follows:

---First published in.2017 as GB/T 33670-2017;

---This is the first revision. Climate year assessment methods

1 Scope

GB/T 33670-2026 is the Chinese national standard covering grading a year's climate as a whole - combining temperature, precipitation and the disasters that occurred into an assessment of whether the year was good, ordinary or bad, which is the figure that goes into agricultural and economic reviews. It replaces GB/T 33670-2017 and has been in force since 1 July 2026, with the drought and cold winter grading standards revised alongside it. It was issued on 31 March 2026 and has been in force since 1 July 2026, replacing GB/T 33670-2017. The document is under the responsibility of the China Meteorological Administration. This page is published from the official record of the 2026 edition; the clause text of a standard this recent is not yet in circulation, and the figures, limits and tables it contains are those of the document itself, delivered in full with the English translation.

This document describes methods for assessing the degree of temperature deviation, precipitation deviation, and climate anomaly in a climate year. This document applies to climate year assessments at the national, regional, and single-station levels.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 20481-2026 Meteorological Drought Classification

3 Terms and Definitions

The following terms and definitions apply to this document.

3.1 climatological normal Climate Normal value The average values of meteorological elements over the most recent three consecutive decades.

Note. According to the World Meteorological Organization (WMO) regulations, climate averages are updated every decadal. For example, for the period from.2011 to 2020, the 1981 values are used. The average value from.1991 to.2010 is used as its climate average; for the period from 2021 to 2030, the average value from.1991 to 2020 is used as its climate average. Average; and so on. [Source: GB/T 21983-2020, 2.2, with modifications]

3.2 annual climatic status The characteristics of climate elements for a given year are determined based on the degree of anomalies in the warming index, cold index, dryness index, and wetness index.

3.3 An index that comprehensively reflects the degree of higher-than-normal temperatures among the climate elements of a given year.

3.4 An index that comprehensively reflects the degree of low temperature among the climatic elements of a given year.

3.5 An index that comprehensively reflects the degree of above-average precipitation among the climate elements of a given year.

3.6 An index that comprehensively reflects the degree of precipitation below average in a given year's climate characteristics.