The province of Lamphun is in the upper-northern part of Thailand. Its distance from Bangkok is 689 kilometres on Highway 11 (Asian Highway), 724 kilometres on Phahonyothin Highway and 729 kilometres by rail. It is located between latitude 18ºN and longitude 99ºE. It is one of the provinces in the upper-northern part of Thailand. It is only 22 kilometres from Chiang Mai. Lamphun has a potential to be developed into the centre of the upper-northern part and Mekong Sub-region or the economic rectangular together with Chiang Mai.
Lamphun province is the smallest province among the provinces in the upper-northern part of Thailand. Its area is approximately 4,505.882 sq.km. or approximately 2,815,675 Rai. This amounts to 4.85 percent of the area of the upper-northern part of Thailand. The widest distance of Lamphun is approximately 43 kilometres while the north-south distance is 136 kilometres.
To the north, Lamphun borders Saraphee and San Kampaeng districts of Chiang Mai.
To the south, Lamphun borders Toen district of Lampang and Sam Ngao district of Tak.
To the east, Lamphun borders Hang Chat, Sop Prab and Serm Ngam districts of Lampang.
To the west, Lamphun borders Hod, Chom Tong, Hang Dong, San Pa Tong districts of Chiang Mai.
The province of Lamphun is situated in the north of Thailand. It has a tropical and warm climate. In the north, it is rather cold. However as it is located further inland away from the sea, its dry season is long and the weather is hot to very hot in the summer. Lamphun province has three distinct seasons; the summer is from March to April; monsoon season is from May to October and winter is from November to February. Both winter and summer are in the dry season of 6 months consecutively. For the remaining 6 months, the weather is not as hot as in the summer and not as cold as in the winter. The temperature is in between the mentioned two seasons.