Which spectral series of hydrogen lies entirely in the ultraviolet region?

Lyman series arises from transitions with $n_1 = 1$ (electron falls into the ground state). The shortest-wavelength line in this series corresponds to $n_2 = \infty$, giving $\lambda \approx 91\,\text{nm}$, well inside the UV region. Balmer (visible) has $n_1 = 2$; Paschen, Brackett, Pfund all have $n_1 \ge 3$ and lie in the infrared.