Recent advances in MOVPE growth and heterostructure fabrication technology mean that infrared detector arrays based on Hg1-xCdxTe now have the potential to produce high performance imagery when operated in the temperature range 150-200 K. This has a number of system advantages including reduced cooler power consumption and increased cooler life. This paper reports the fabrication and assessment of a MW staring array with a cut-off of 4 mum at 150 K for intermediate temperature operation. Near background limited (BLIP) performance was achieved at temperatures up to 180 K with a median NETD better than 12 mK. Above this temperature, the array still operates normally however there is an exponential increase in the number of noisy pixels, and the median NETD degrades more rapidly than predicted from Shot noise. This behavior is consistent with increased low frequency or 1/f noise at the higher temperatures. This excess noise is not a fundamental limitation and if it could be eliminated, the array would remain close to BLIP up to 200 K.