Although onsets do not arbitrate stress placement in English categorically, results from Kelly (2004) and Ryan (2014) suggest that English stress assignment is nevertheless sensitive to onset complexity. Phonetic work on languages in which onsets participate in categorical weight criteria shows that onsets contribute to stress assignment through their phonetic impact on the nucleus, primarily through their effect on nucleus energy (Gordon, 2005). Onsets in English probabilistically participate in weight-based processes, and here it is predicted that they impact the phonetic realization of the syllable similar to the way that onsets do in languages with categorical onset weight criteria. To test this prediction, speakers in this study produced monosyllabic English words varying in onset complexity, and measures of duration, intensity, and f0 were collected. Results of the current study are consistent with the predictions of Gordon’s perceptual account of categorical weight, showing that integrated intensity of the rime is incapable of driving onset weight behavior in English. Furthermore, results indicate that onsets impact the shape of the intensity envelope in a manner consistent with explanations for gradient onset weight that appeal to onset influence on the perceptual center (Ryan, 2014). Together, these results show that cues to gradient weight act independently of primary cues to categorical weight to probabilistically impact weight sensitive stress assignment in English.