Norrbotten Län in Sweden is located to the south and further southeast is a shorter border with Lapland Province in Finland.

On 1 July 2006, the Northern Sami name for the county, Romsa, was granted official status along with Troms.

The coat of arms of Troms was made by Hallvard Trætteberg (1898–1987) and adopted by royal resolution on 15 January 1960.

The official blazon in Norwegian ("På rød bunn en gull griff") translates to "On a field Gules a griffin [segreant] Or.

"[7] Trætteberg chose to have the griffin as charge because that animal was the symbol of the mighty clan of Bjarne Erlingsson on Bjarkøy in the 13th century.

Some of these islands, most noteworthy Senja, have a rugged outer coast with steep mountains, and a more calm eastern shore.

Starting in the south, the largest fjords are Vågsfjorden, Andfjorden (partially in Nordland county), Malangen, Balsfjorden, Ullsfjorden, Lyngen, and Kvænangen.

Located at a latitude of nearly 70°N, Troms has short, cool summers, but fairly mild winters along the coast due to the temperate sea; Torsvåg Lighthouse in Karlsøy Municipality has January 24-hr average of −1 °C (30 °F).

Temperatures are typically below freezing for about 5 months (8 months in the mountains), from early November to the beginning of April, but coastal areas are moderated by the sea: with more than 130 years of official weather recordings, the coldest winter temperature ever recorded in Tromsø is −20.1 °C (−4.2 °F) in February 1985.

Skibotn (elevation: 46 m or 151 ft) in Storfjord Municipality is the location in Norway which has recorded the most days per year with clear skies (no clouds).

As a consequence of this, the length of daylight increases (late winter and spring) or decreases (autumn) by 10 minutes from one day to the next.

[11] Moose, red fox, hare, stoat, and small rodents are common in all of Troms county.

[14] The inland valleys, like Østerdalen (with Altevatnet), Kirkesdalen, Dividalen, Rostadalen, Signaldalen, and Skibotndalen, are perfect for summer hiking, with their varied nature, mostly dry climate and not too difficult terrain, although there are many accessible mountains for energetic hikers.

[15] The valley ends 120 km (75 mi) southeast of Storslett, as the vast and more barren Finnmarksvidda plateau takes over.

Harstad is a commercial centre for the southern part of the county, and has been chosen by Statoil as its main office in Northern Norway.

For this reason passenger boats are fairly popular, for example between Tromsø and Harstad, and there are also commercial flights inside the county of Troms.

[18] Troms has been settled since the early Stone Age, and there are prehistoric rock carvings at several locations (for instance Ibestad and Balsfjord).

[20] From the 10th century, Norse settlements start to appear along the coast further north, reaching into what is today the county of Finnmark.

The Kven residents of Troms are largely descendants of Finnish immigrants who arrived in the area before the 19th century from Finland because of war and famine.

They settled mainly in the northeastern part of Troms, in the municipalities of Kvænangen, Nordreisa, Skjervøy, Gáivuotna-Kåfjord and Storfjord, and some also reached Balsfjord and Lyngen.