This is a time-series record from nitrate + nitrite (∑NOx) and dissolved silica (DSi) collected using in situ lab-on-chip sensors that were deployed in a glacier-fed fjord (Nuup Kangerlua) between 14th June to 13th September 2019. The sensors (along with a conductivity, temperature and depth (CTD) probe) were attached to a frame that was anchored to a cliff and submerged at an average depth of 5 m. The sensors were programmed to draw in ambient water (through 0.45 µm pore-size 13 mm diameter polyethersulfone inlet filters) and measure its nutrient concentration every 12 hours. Each measurement was accompanied by the measurement of an onboard calibration standard and a blank solution (artificial seawater). The accompanying CTD was set to sample every 10 minutes. During a three-month monitoring period ∑NOx varied between 0.05 and 10.07 µM (± 0.2 μM), while DSi varied between 0.35 and 14.98 µM (± 0.5 μM). The dataset also contains CTD data from a cast taken nearby when the sensors were recovered.