  NIKA2 is a dual-band millimetric continuum camera of 2900 Kinetic Inductance
Detectors (KID), operating at $150$ and $260\,\rm{GHz}$, installed at the IRAM
30-meter telescope. We present the performance assessment of NIKA2 after one
year of observation using a dedicated point-source calibration method, referred
to as the \emph{baseline} method. Using a large data set acquired between
January 2017 and February 2018 that span the whole range of observing
elevations and atmospheric conditions encountered at the IRAM 30-m telescope,
we test the stability of the performance parameters. We report an instantaneous
field of view (FOV) of 6.5' in diameter, filled with an average fraction of
$84\%$ and $90\%$ of valid detectors at $150$ and $260\,\rm{GHz}$,
respectively. The beam pattern is characterized by a FWHM of $17.6'' \pm 0.1''$
and $11.1''\pm 0.2''$, and a beam efficiency of $77\% \pm 2\%$ and $55\% \pm
3\%$ at $150$ and $260\,\rm{GHz}$, respectively. The rms calibration
uncertainties are about $3\%$ at $150\,\rm{GHz}$ and $6\%$ at $260\,\rm{GHz}$.
The absolute calibration uncertainties are of $5\%$ and the systematic
calibration uncertainties evaluated at the IRAM 30-m reference Winter observing
conditions are below $1\%$ in both channels. The noise equivalent flux density
(NEFD) at $150$ and $260\,\rm{GHz}$ are of $9 \pm 1\, \rm{mJy}\cdot s^{1/2}$
and $30 \pm 3\, \rm{mJy}\cdot s^{1/2}$. This state-of-the-art performance
confers NIKA2 with mapping speeds of $1388 \pm 174$ and $111 \pm 11
\,\rm{arcmin}^2\cdot \rm{mJy}^{-2}\cdot \rm{h}^{-1}$ at $150$ and
$260\,\rm{GHz}$. With these unique capabilities of fast dual-band mapping at
high (better that 18'') angular resolution, NIKA2 is providing an unprecedented
view of the millimetre Universe.
