Tunsbergdalsbreen is the longest outlet glacier of Jostedalsbreen. The mass balance was measured in seven years, from 1966 to 1972.
| Year | Front variation (m) | Cumulative front variation (m) |
|---|---|---|
| 1900 | 0 | Start |
| 1903 | -34 | -34 |
| 1907 | -1 | -35 |
| 1908 | -2 | -37 |
| 1909 | -10 | -47 |
| 1910 | -15 | -62 |
| 1911 | 3 | -59 |
| 1912 | -67 | -126 |
| 1913 | -3 | -129 |
| 1914 | -26 | -155 |
| 1915 | -8 | -163 |
| 1916 | -17 | -180 |
| 1917 | -64 | -244 |
| 1918 | -5 | -249 |
| 1919 | -14 | -263 |
| 1920 | -4 | -267 |
| 1921 | -10 | -277 |
| 1922 | -34 | -311 |
| 1923 | -23 | -334 |
| 1924 | -13 | -347 |
| 1925 | -10 | -357 |
| 1926 | -10 | -367 |
| 1927 | -14 | -381 |
| 1928 | -10 | -391 |
| 1929 | -8 | -399 |
| 1930 | -23 | -422 |
| 1931 | -15 | -437 |
| 1932 | -12 | -449 |
| 1933 | -8 | -457 |
| 1934 | -13 | -470 |
| 1935 | -20 | -490 |
| 1936 | -26 | -516 |
| 1937 | -37 | -553 |
| 1938 | -11 | -564 |
| 1939 | -19 | -583 |
| 1940 | -19 | -602 |
| 1941 | -5 | -607 |
| 1942 | -5 | -612 |
| 1943 | -17 | -629 |
| 1944 | -18 | -647 |
| 1945 | -37 | -684 |
| 1946 | -17 | -701 |
| 1947 | -43 | -744 |
| 1948 | -22 | -766 |
| 1949 | -54 | -820 |
| 1950 | -23 | -843 |
| 1951 | -12 | -855 |
| 1952 | -17 | -872 |
| 1953 | -16 | -888 |
| 1954 | -20 | -908 |
| 1955 | -12 | -920 |
| 1956 | -10 | -930 |
| 1957 | -6 | -936 |
| 1959 | -5 | -941 |
| 1960 | -15 | -956 |
| 1961 | -27 | -983 |
| 1963 | -23 | -1006 |
| 1964 | -24 | -1030 |
| 1965 | -28 | -1058 |
| 1973 | -68 | -1126 |
| 1974 | -4 | -1130 |
| 1975 | -11 | -1141 |
| 1976 | -6 | -1147 |
| Year | Winter balance (m.w.e.) | Summer balance (m.w.e.) | Annual balance (m.w.e.) |
|---|---|---|---|
| 1966 | 1.65 | -2.55 | -0.90 |
| 1967 | 3.43 | -1.41 | 2.02 |
| 1968 | 2.81 | -2.55 | 0.26 |
| 1969 | 1.56 | -3.15 | -1.59 |
| 1970 | 1.58 | -2.30 | -0.72 |
| 1971 | 2.43 | -1.71 | 0.72 |
| 1972 | 2.06 | -2.44 | -0.37 |