The MCU. Buddhist University in Chiang Mai offers a one day (every Friday) meditation workshop or a two day (every Tuesday/Wednesday) meditation workshop in a Buddhist temple. Currently taught by Phra KK (Monk KK) who speaks very good English. The one day course is for free, the two day course comes with a little fee as you are going to eat and sleep there overnight. It costs 500 Baht + 300 Baht for white cloth if you don’t have it with you.

There is also a free Monk Chat on every work day from 5.00 to 7.00 pm.

You will find more information about both programs at:
http://www.mrlearnning.com
http://www.monkchat.net/

German speakers, can read the following article:
http://www.spiegel.de/reise/fernweh/meditations-retreat-in-chiang-mai-in-thailand-kampf-dem-inneren-affen-a-1110936.html