jma_logo Welcome to TCC wmo_logo
World Climate
Climate System Monitoring
El Niño Monitoring
NWP Model Prediction
Global Warming
Climate in Japan
Training Module
Press release
HOME >Climate System Monitoring > Monthly Highlights on the Climate System

Monthly Highlights on the Climate System

'Monthly Highlights on the Climate System' has been issued in PDF format since March 2007 as a monthly bulletin focusing on the monthly highlights of the monitoring results.

Highlights in April 2018

- It is considered that La Niña conditions continue in the equatorial Pacific (see El Niño Outlook updated on 11 May 2018).
- Monthly mean temperatures were significantly above normal in eastern and western Japan.
- Monthly precipitation amounts were significantly above normal on the Sea of Japan side of eastern Japan.
- Monthly sunshine durations were significantly above normal on the Pacific side of western Japan and in Okinawa/Amami.
- Monthly mean temperatures were extremely high from eastern Japan to central China, and in and around Europe.
- The active phase of equatorial intraseasonal oscillation propagated eastward from South Africa to the Indian Ocean during early to mid-April, but after that its amplitude became small.
- In the 500-hPa height field, a wave train was dominant from North America through Europe to the seas east of Japan, with positive anomaly from the northern part of East Asia to the seas east of Japan and negative anomaly from eastern Canada to the seas west of the UK, respectively. Associated with a blocking high over the East Siberian Sea, negative anomaly was seen in and around the Kamchatka Peninsula.
- Temperatures at 850-hPa were above normal over the East Siberian Sea, Europe and East Asia, and below normal over the central and eastern parts of North America.

Full version (PDF)

The descriptions until April 2011 are based on the old normal (i.e., the 1979 - 2004 average).
The descriptions until January 2014 are based on the JRA-25/JCDAS datasets.

Figures and Tables

If you would like to subscribe to Monthly Highlights on the Climate System, please send an email to

with your name, affiliation, country and email address.
page top

Tokyo Climate Center, Climate Prediction Division, 1-3-4 Otemachi, Chiyoda-ku, Tokyo, Japan.
Copyright(C) 2002. Japan Meteorological Agency. - Legal Notice -