 Several glaciers , notably the much @-@ visited Fox and Franz Josef Glaciers on New Zealand 's West Coast , have periodically advanced , especially during the 1990s , but the scale of these advances is small when compared to 20th @-@ century retreat . Both are more than 2 @.@ 5 km ( 1 @.@ 6 mi ) shorter than a century ago . These large , rapidly flowing glaciers situated on steep slopes have been very reactive to small mass @-@ balance changes . A few years of conditions favorable to glacier advance , such as more westerly winds and a resulting increase in snowfall , are rapidly echoed in a corresponding advance , followed by equally rapid retreat when those favorable conditions end . The glaciers that have been advancing in a few locations in New Zealand have been doing so due to transient local weather conditions , which have brought more precipitation and cloudier , cooler summers since 2002 . 
