  We present two-dimensional near-infrared temperature maps of the canonical
hot Jupiter WASP-43b using a phase-curve observation with JWST NIRSpec/G395H.
From the white-light planetary transit, we improve constraints on the planet's
orbital parameters and measure a planet-to-star radius ratio of
$0.15883^{+0.00056}_{-0.00053}$. Using the white-light phase curve, we measure
a longitude of maximum brightness of $6.9^{+0^\circ.5}_{-0^\circ.5}$ east of
the substellar point and a phase-curve offset of
$10.0^{+0^\circ.8}_{-0^\circ.8}$. We also find an $\approx4\sigma$ detection of
a latitudinal hotspot offset of $-13.4^{+3^\circ.2}_{-1^\circ.7}$, the first
significant detection of a non-equatorial hotspot in an exoplanet atmosphere.
We show that this detection is robust to variations within planetary parameter
uncertainties, but only if the transit is used to improve constraints, showing
the importance of transit observations to eclipse mapping. Maps retrieved from
the NRS1 and NRS2 detectors are similar, with hotspot locations consistent
between the two detectors at the $1\sigma$ level. Our JWST data show brighter
(hotter) nightsides and a dimmer (colder) dayside at the shorter wavelengths
relative to fits to \textit{Spitzer} 3.6 and 4.5 \microns\ phase curves.
Through comparison between our phase curves and a set of general circulation
models, we find evidence for clouds on the nightside and atmospheric drag or
high metallicity reducing the eastward hotspot offset.
